* [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels
@ 2013-04-08 18:59 David Vrabel
2013-04-08 18:59 ` [PATCH 1/8] x86: give FIX_EFI_MPF its own fixmap entry David Vrabel
` (7 more replies)
0 siblings, 8 replies; 34+ messages in thread
From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw)
To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell
The series improves the kexec hypercall by making Xen responsible for
loading and relocating the image. This allows kexec to be usable by
pv-ops kernels and should allow kexec to be usable from a HVM or PVH
privileged domain.
The first patch is a simple clean-up.
The second patch allows hypercall structures to be ABI compatible
between 32- and 64-bit guests (by reusing stuff present for domctls
and sysctls). This seems better than having to keep adding compat
handling for new hypercalls etc.
Patch 3 introduces the new ABI.
Patch 4 and 5 nearly completely reimplement the kexec load, unload and
exec sub-ops. The old load_v1 sub-op is then implemented on top of
the new code.
Patch 6 calls the kexec image when dom0 crashes. This avoids having
to alter dom0 kernels to do a exec sub-op call on crash -- a
SHUTDOWN_crash by dom0 will trigger the kexec.
Patches 7 and 8 add the libxc API for the kexec calls. These have
been acked-by Ian Campbell already.
The required patch series for kexec-tools will be posted shortly.
Changes since v2:
- Provide old struct xen_kexec_load if __XEN_INTERFACE_VERSION__ < 4.3
- Adjust new struct xen_kexec_load to avoid unnecessary padding.
- Use domheap pages for the image and control pages.
- Remove the DBG() macros from the reloc code.
David
_______________________________________________
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kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec
^ permalink raw reply [flat|nested] 34+ messages in thread* [PATCH 1/8] x86: give FIX_EFI_MPF its own fixmap entry 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel @ 2013-04-08 18:59 ` David Vrabel 2013-04-09 7:27 ` [Xen-devel] " Jan Beulich 2013-04-08 18:59 ` [PATCH 2/8] xen: make GUEST_HANDLE_64() and uint64_aligned_t available everywhere David Vrabel ` (6 subsequent siblings) 7 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw) To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell From: David Vrabel <david.vrabel@citrix.com> FIX_EFI_MPF was the same as FIX_KEXEC_BASE_0 which is going away. So add its own entry. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- xen/arch/x86/mpparse.c | 2 -- xen/include/asm-x86/fixmap.h | 1 + 2 files changed, 1 insertions(+), 2 deletions(-) diff --git a/xen/arch/x86/mpparse.c b/xen/arch/x86/mpparse.c index 97ab5d3..f13ba93 100644 --- a/xen/arch/x86/mpparse.c +++ b/xen/arch/x86/mpparse.c @@ -538,8 +538,6 @@ static inline void __init construct_default_ISA_mptable(int mpc_default_type) } } -#define FIX_EFI_MPF FIX_KEXEC_BASE_0 - static __init void efi_unmap_mpf(void) { if (efi_enabled) diff --git a/xen/include/asm-x86/fixmap.h b/xen/include/asm-x86/fixmap.h index d026d78..2eefcf4 100644 --- a/xen/include/asm-x86/fixmap.h +++ b/xen/include/asm-x86/fixmap.h @@ -71,6 +71,7 @@ enum fixed_addresses { FIX_APEI_RANGE_BASE, FIX_APEI_RANGE_END = FIX_APEI_RANGE_BASE + FIX_APEI_RANGE_MAX -1, FIX_IGD_MMIO, + FIX_EFI_MPF, __end_of_fixed_addresses }; -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* Re: [Xen-devel] [PATCH 1/8] x86: give FIX_EFI_MPF its own fixmap entry 2013-04-08 18:59 ` [PATCH 1/8] x86: give FIX_EFI_MPF its own fixmap entry David Vrabel @ 2013-04-09 7:27 ` Jan Beulich 2013-04-09 16:15 ` David Vrabel 0 siblings, 1 reply; 34+ messages in thread From: Jan Beulich @ 2013-04-09 7:27 UTC (permalink / raw) To: David Vrabel; +Cc: kexec, Daniel Kiper, Ian Jackson, Ian Campbell, xen-devel >>> On 08.04.13 at 20:59, David Vrabel <david.vrabel@citrix.com> wrote: > FIX_EFI_MPF was the same as FIX_KEXEC_BASE_0 which is going away. So > add its own entry. To be honest, no matter how small the wastage, I'd prefer reusing another entry over creating a new one. FIX_TBOOT_MAP_ADDRESS seems like a reasonable fit (which we also don't have to expect to go away, unless tboot support would get ripped out altogether). This is not the least because sane UEFI systems aren't expected to have MPS tables anyway (i.e. the entry, if separate, would likely _never_ be used in reality), it's just that the specification allows for it. Jan _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [Xen-devel] [PATCH 1/8] x86: give FIX_EFI_MPF its own fixmap entry 2013-04-09 7:27 ` [Xen-devel] " Jan Beulich @ 2013-04-09 16:15 ` David Vrabel 0 siblings, 0 replies; 34+ messages in thread From: David Vrabel @ 2013-04-09 16:15 UTC (permalink / raw) To: Jan Beulich Cc: kexec@lists.infradead.org, Daniel Kiper, Ian Jackson, Ian Campbell, xen-devel@lists.xen.org On 09/04/13 08:27, Jan Beulich wrote: >>>> On 08.04.13 at 20:59, David Vrabel <david.vrabel@citrix.com> wrote: >> FIX_EFI_MPF was the same as FIX_KEXEC_BASE_0 which is going away. So >> add its own entry. > > To be honest, no matter how small the wastage, I'd prefer reusing > another entry over creating a new one. FIX_TBOOT_MAP_ADDRESS > seems like a reasonable fit (which we also don't have to expect to > go away, unless tboot support would get ripped out altogether). > This is not the least because sane UEFI systems aren't expected to > have MPS tables anyway (i.e. the entry, if separate, would likely > _never_ be used in reality), it's just that the specification allows for > it. This patch added one entry and patch 5 removes 68 entries so this series is a big gain as is. It doesn't seem productive to further improve this at this time. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* [PATCH 2/8] xen: make GUEST_HANDLE_64() and uint64_aligned_t available everywhere 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel 2013-04-08 18:59 ` [PATCH 1/8] x86: give FIX_EFI_MPF its own fixmap entry David Vrabel @ 2013-04-08 18:59 ` David Vrabel 2013-04-08 18:59 ` [PATCH 3/8] kexec: add public interface for improved load/unload sub-ops David Vrabel ` (5 subsequent siblings) 7 siblings, 0 replies; 34+ messages in thread From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw) To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell From: David Vrabel <david.vrabel@citrix.com> GUEST_HANDLE_64() and uint64_aligned_t allow hypercall ABI structures to be identical (binary compatible) for 32 and 64-bit guests. They are currently limited to only being available for use in sysctls and domctls. Relax this limit so it may be used by any new structures. There is a minimal cost for 32-bit guests on 64-but hypervisors as set_guest_handle() needs to 0 the whole field on GUEST_HANDLE_64() handles, but this is expected to be less than the overhead of having to translate compat structures. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- xen/include/public/arch-x86/xen-x86_32.h | 4 +--- xen/include/public/xen.h | 13 ++++++++----- 2 files changed, 9 insertions(+), 8 deletions(-) diff --git a/xen/include/public/arch-x86/xen-x86_32.h b/xen/include/public/arch-x86/xen-x86_32.h index 1504191..f6b4f49 100644 --- a/xen/include/public/arch-x86/xen-x86_32.h +++ b/xen/include/public/arch-x86/xen-x86_32.h @@ -91,8 +91,7 @@ #define machine_to_phys_mapping ((unsigned long *)MACH2PHYS_VIRT_START) #endif -/* 32-/64-bit invariability for control interfaces (domctl/sysctl). */ -#if defined(__XEN__) || defined(__XEN_TOOLS__) +/* 32-/64-bit invariability. */ #undef ___DEFINE_XEN_GUEST_HANDLE #define ___DEFINE_XEN_GUEST_HANDLE(name, type) \ typedef struct { type *p; } \ @@ -107,7 +106,6 @@ #define uint64_aligned_t uint64_t __attribute__((aligned(8))) #define __XEN_GUEST_HANDLE_64(name) __guest_handle_64_ ## name #define XEN_GUEST_HANDLE_64(name) __XEN_GUEST_HANDLE_64(name) -#endif #ifndef __ASSEMBLY__ diff --git a/xen/include/public/xen.h b/xen/include/public/xen.h index e9431e2..af421a2 100644 --- a/xen/include/public/xen.h +++ b/xen/include/public/xen.h @@ -840,9 +840,14 @@ __DEFINE_XEN_GUEST_HANDLE(uint64, uint64_t); #endif /* !__ASSEMBLY__ */ -/* Default definitions for macros used by domctl/sysctl. */ -#if defined(__XEN__) || defined(__XEN_TOOLS__) - +/* + * Default definitions for 32/64-bit invariant macros. + * + * Use these in ABI structures that should be identical for 32 and + * 64-bit guests. There is some (very small) overhead in using + * XEN_GUEST_HANDLE_64() instead of XEN_GUEST_HANDLE() so avoid for + * very hot paths. + */ #ifndef uint64_aligned_t #define uint64_aligned_t uint64_t #endif @@ -857,8 +862,6 @@ struct xenctl_cpumap { }; #endif -#endif /* defined(__XEN__) || defined(__XEN_TOOLS__) */ - #endif /* __XEN_PUBLIC_XEN_H__ */ /* -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* [PATCH 3/8] kexec: add public interface for improved load/unload sub-ops 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel 2013-04-08 18:59 ` [PATCH 1/8] x86: give FIX_EFI_MPF its own fixmap entry David Vrabel 2013-04-08 18:59 ` [PATCH 2/8] xen: make GUEST_HANDLE_64() and uint64_aligned_t available everywhere David Vrabel @ 2013-04-08 18:59 ` David Vrabel 2013-04-09 7:32 ` [Xen-devel] " Jan Beulich 2013-04-08 18:59 ` [PATCH 4/8] kexec: add infrastructure for handling kexec images David Vrabel ` (4 subsequent siblings) 7 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw) To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell From: David Vrabel <david.vrabel@citrix.com> Add replacement KEXEC_CMD_load and KEXEC_CMD_unload sub-ops to the kexec hypercall. These new sub-ops allow a priviledged guest to provide the image data to be loaded into Xen memory or the crash region instead of guests loading the image data themselves and providing the relocation code and metadata. The old interface is provided to guests requesting an interface version prior to 4.3. Signed-off: David Vrabel <david.vrabel@citrix.com> --- xen/common/kexec.c | 12 ++++---- xen/include/public/kexec.h | 65 +++++++++++++++++++++++++++++++++++++++++--- 2 files changed, 67 insertions(+), 10 deletions(-) diff --git a/xen/common/kexec.c b/xen/common/kexec.c index 7b04c1c..f2bda59 100644 --- a/xen/common/kexec.c +++ b/xen/common/kexec.c @@ -733,7 +733,7 @@ static void crash_save_vmcoreinfo(void) #endif } -static int kexec_load_unload_internal(unsigned long op, xen_kexec_load_t *load) +static int kexec_load_unload_internal(unsigned long op, xen_kexec_load_v1_t *load) { xen_kexec_image_t *image; int base, bit, pos; @@ -780,7 +780,7 @@ static int kexec_load_unload_internal(unsigned long op, xen_kexec_load_t *load) static int kexec_load_unload(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg) { - xen_kexec_load_t load; + xen_kexec_load_v1_t load; if ( unlikely(copy_from_guest(&load, uarg, 1)) ) return -EFAULT; @@ -792,8 +792,8 @@ static int kexec_load_unload_compat(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg) { #ifdef CONFIG_COMPAT - compat_kexec_load_t compat_load; - xen_kexec_load_t load; + compat_kexec_load_v1_t compat_load; + xen_kexec_load_v1_t load; if ( unlikely(copy_from_guest(&compat_load, uarg, 1)) ) return -EFAULT; @@ -865,8 +865,8 @@ static int do_kexec_op_internal(unsigned long op, else ret = kexec_get_range(uarg); break; - case KEXEC_CMD_kexec_load: - case KEXEC_CMD_kexec_unload: + case KEXEC_CMD_kexec_load_v1: + case KEXEC_CMD_kexec_unload_v1: spin_lock_irqsave(&kexec_lock, flags); if (!test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags)) { diff --git a/xen/include/public/kexec.h b/xen/include/public/kexec.h index 36409ff..1c1a704 100644 --- a/xen/include/public/kexec.h +++ b/xen/include/public/kexec.h @@ -116,12 +116,12 @@ typedef struct xen_kexec_exec { * type == KEXEC_TYPE_DEFAULT or KEXEC_TYPE_CRASH [in] * image == relocation information for kexec (ignored for unload) [in] */ -#define KEXEC_CMD_kexec_load 1 -#define KEXEC_CMD_kexec_unload 2 -typedef struct xen_kexec_load { +#define KEXEC_CMD_kexec_load_v1 1 /* obsolete since 0x00040300 */ +#define KEXEC_CMD_kexec_unload_v1 2 /* obsolete since 0x00040300 */ +typedef struct xen_kexec_load_v1 { int type; xen_kexec_image_t image; -} xen_kexec_load_t; +} xen_kexec_load_v1_t; #define KEXEC_RANGE_MA_CRASH 0 /* machine address and size of crash area */ #define KEXEC_RANGE_MA_XEN 1 /* machine address and size of Xen itself */ @@ -152,6 +152,63 @@ typedef struct xen_kexec_range { unsigned long start; } xen_kexec_range_t; +#if __XEN_INTERFACE_VERSION__ >= 0x00040300 +/* + * A contiguous chunk of a kexec image and it's destination machine + * address. + */ +typedef struct xen_kexec_segment { + XEN_GUEST_HANDLE_64(const_void) buf; + uint64_t buf_size; + uint64_t dest_maddr; + uint64_t dest_size; +} xen_kexec_segment_t; +DEFINE_XEN_GUEST_HANDLE(xen_kexec_segment_t); + +/* + * Load a kexec image into memory. + * + * For KEXEC_TYPE_DEFAULT images, the segments may be anywhere in RAM. + * The image is relocated prior to being executed. + * + * For KEXEC_TYPE_CRASH images, each segment of the image must reside + * in the memory region reserved for kexec (KEXEC_RANGE_MA_CRASH) and + * the entry point must be within the image. The caller is responsible + * for ensuring that multiple images do not overlap. + */ + +#define KEXEC_CMD_kexec_load 4 +typedef struct xen_kexec_load { + uint8_t type; /* One of KEXEC_TYPE_* */ + uint16_t arch; /* ELF machine type (EM_*). */ + uint32_t nr_segments; + XEN_GUEST_HANDLE_64(xen_kexec_segment_t) segments; + uint64_t entry_maddr; /* image entry point machine address. */ +} xen_kexec_load_t; +DEFINE_XEN_GUEST_HANDLE(xen_kexec_load_t); + +/* + * Unload a kexec image. + * + * Type must be one of KEXEC_TYPE_DEFAULT or KEXEC_TYPE_CRASH. + */ +#define KEXEC_CMD_kexec_unload 5 +typedef struct xen_kexec_unload { + uint8_t type; +} xen_kexec_unload_t; +DEFINE_XEN_GUEST_HANDLE(xen_kexec_unload_t); + +#else /* __XEN_INTERFACE_VERSION__ < 0x00040300 */ + +#define KEXEC_CMD_kexec_load KEXEC_CMD_kexec_load_v1 +#define KEXEC_CMD_kexec_unload KEXEC_CMD_kexec_unload_v1 +typedef struct xen_kexec_load { + int type; + xen_kexec_image_t image; +} xen_kexec_load_t; + +#endif + #endif /* _XEN_PUBLIC_KEXEC_H */ /* -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* Re: [Xen-devel] [PATCH 3/8] kexec: add public interface for improved load/unload sub-ops 2013-04-08 18:59 ` [PATCH 3/8] kexec: add public interface for improved load/unload sub-ops David Vrabel @ 2013-04-09 7:32 ` Jan Beulich 2013-04-12 11:56 ` David Vrabel 0 siblings, 1 reply; 34+ messages in thread From: Jan Beulich @ 2013-04-09 7:32 UTC (permalink / raw) To: David Vrabel; +Cc: kexec, Daniel Kiper, Ian Jackson, Ian Campbell, xen-devel >>> On 08.04.13 at 20:59, David Vrabel <david.vrabel@citrix.com> wrote: > @@ -152,6 +152,63 @@ typedef struct xen_kexec_range { > unsigned long start; > } xen_kexec_range_t; > > +#if __XEN_INTERFACE_VERSION__ >= 0x00040300 > +/* > + * A contiguous chunk of a kexec image and it's destination machine > + * address. > + */ > +typedef struct xen_kexec_segment { > + XEN_GUEST_HANDLE_64(const_void) buf; > + uint64_t buf_size; > + uint64_t dest_maddr; > + uint64_t dest_size; So you made uint64_aligned_t available in the previous patch, but now you don't use it? > +} xen_kexec_segment_t; > +DEFINE_XEN_GUEST_HANDLE(xen_kexec_segment_t); > + > +/* > + * Load a kexec image into memory. > + * > + * For KEXEC_TYPE_DEFAULT images, the segments may be anywhere in RAM. > + * The image is relocated prior to being executed. > + * > + * For KEXEC_TYPE_CRASH images, each segment of the image must reside > + * in the memory region reserved for kexec (KEXEC_RANGE_MA_CRASH) and > + * the entry point must be within the image. The caller is responsible > + * for ensuring that multiple images do not overlap. > + */ > + > +#define KEXEC_CMD_kexec_load 4 > +typedef struct xen_kexec_load { > + uint8_t type; /* One of KEXEC_TYPE_* */ Explicit padding please. > + uint16_t arch; /* ELF machine type (EM_*). */ > + uint32_t nr_segments; > + XEN_GUEST_HANDLE_64(xen_kexec_segment_t) segments; > + uint64_t entry_maddr; /* image entry point machine address. */ > +} xen_kexec_load_t; > +DEFINE_XEN_GUEST_HANDLE(xen_kexec_load_t); > + > +/* > + * Unload a kexec image. > + * > + * Type must be one of KEXEC_TYPE_DEFAULT or KEXEC_TYPE_CRASH. > + */ > +#define KEXEC_CMD_kexec_unload 5 > +typedef struct xen_kexec_unload { > + uint8_t type; > +} xen_kexec_unload_t; > +DEFINE_XEN_GUEST_HANDLE(xen_kexec_unload_t); > + > +#else /* __XEN_INTERFACE_VERSION__ < 0x00040300 */ > + > +#define KEXEC_CMD_kexec_load KEXEC_CMD_kexec_load_v1 > +#define KEXEC_CMD_kexec_unload KEXEC_CMD_kexec_unload_v1 > +typedef struct xen_kexec_load { > + int type; > + xen_kexec_image_t image; > +} xen_kexec_load_t; I don't really like this duplication, but I admit that the alternatives I can think of aren't much better either. Jan _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [Xen-devel] [PATCH 3/8] kexec: add public interface for improved load/unload sub-ops 2013-04-09 7:32 ` [Xen-devel] " Jan Beulich @ 2013-04-12 11:56 ` David Vrabel 2013-04-12 13:01 ` Jan Beulich 0 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-12 11:56 UTC (permalink / raw) To: Jan Beulich Cc: kexec@lists.infradead.org, Daniel Kiper, Ian Jackson, Ian Campbell, xen-devel@lists.xen.org On 09/04/13 08:32, Jan Beulich wrote: >>>> On 08.04.13 at 20:59, David Vrabel <david.vrabel@citrix.com> wrote: >> @@ -152,6 +152,63 @@ typedef struct xen_kexec_range { >> unsigned long start; >> } xen_kexec_range_t; >> >> +#if __XEN_INTERFACE_VERSION__ >= 0x00040300 >> +/* >> + * A contiguous chunk of a kexec image and it's destination machine >> + * address. >> + */ >> +typedef struct xen_kexec_segment { >> + XEN_GUEST_HANDLE_64(const_void) buf; >> + uint64_t buf_size; >> + uint64_t dest_maddr; >> + uint64_t dest_size; > > So you made uint64_aligned_t available in the previous patch, > but now you don't use it? It's not needed here. Should I use uint64_aligned_t anyway? It was easier to make both XEN_GUEST_HANDLE_64() and uint64_aligned_t available than to make only one. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [Xen-devel] [PATCH 3/8] kexec: add public interface for improved load/unload sub-ops 2013-04-12 11:56 ` David Vrabel @ 2013-04-12 13:01 ` Jan Beulich 0 siblings, 0 replies; 34+ messages in thread From: Jan Beulich @ 2013-04-12 13:01 UTC (permalink / raw) To: David Vrabel Cc: kexec@lists.infradead.org, Daniel Kiper, Ian Jackson, Ian Campbell, xen-devel@lists.xen.org >>> On 12.04.13 at 13:56, David Vrabel <david.vrabel@citrix.com> wrote: > On 09/04/13 08:32, Jan Beulich wrote: >>>>> On 08.04.13 at 20:59, David Vrabel <david.vrabel@citrix.com> wrote: >>> @@ -152,6 +152,63 @@ typedef struct xen_kexec_range { >>> unsigned long start; >>> } xen_kexec_range_t; >>> >>> +#if __XEN_INTERFACE_VERSION__ >= 0x00040300 >>> +/* >>> + * A contiguous chunk of a kexec image and it's destination machine >>> + * address. >>> + */ >>> +typedef struct xen_kexec_segment { >>> + XEN_GUEST_HANDLE_64(const_void) buf; >>> + uint64_t buf_size; >>> + uint64_t dest_maddr; >>> + uint64_t dest_size; >> >> So you made uint64_aligned_t available in the previous patch, >> but now you don't use it? > > It's not needed here. Should I use uint64_aligned_t anyway? > > It was easier to make both XEN_GUEST_HANDLE_64() and uint64_aligned_t > available than to make only one. Ah, okay. And now that I think about it again, perhaps the less extensions we need to use, the better. So I guess it's fine to keep things the way they are in this regard. Jan _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* [PATCH 4/8] kexec: add infrastructure for handling kexec images 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel ` (2 preceding siblings ...) 2013-04-08 18:59 ` [PATCH 3/8] kexec: add public interface for improved load/unload sub-ops David Vrabel @ 2013-04-08 18:59 ` David Vrabel 2013-04-09 7:44 ` [Xen-devel] " Jan Beulich 2013-04-08 18:59 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel ` (3 subsequent siblings) 7 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw) To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell From: David Vrabel <david.vrabel@citrix.com> Add the code needed to handle and load kexec images into Xen memory or into the crash region. This is needed for the new KEXEC_CMD_load and KEXEC_CMD_unload hypercall sub-ops. Much of this code is derived from the Linux kernel. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- xen/common/Makefile | 1 + xen/common/kimage.c | 842 ++++++++++++++++++++++++++++++++++++++++++++++ xen/include/xen/kimage.h | 63 ++++ 3 files changed, 906 insertions(+), 0 deletions(-) create mode 100644 xen/common/kimage.c create mode 100644 xen/include/xen/kimage.h diff --git a/xen/common/Makefile b/xen/common/Makefile index 8a0c506..1d12775 100644 --- a/xen/common/Makefile +++ b/xen/common/Makefile @@ -11,6 +11,7 @@ obj-y += irq.o obj-y += kernel.o obj-y += keyhandler.o obj-$(HAS_KEXEC) += kexec.o +obj-$(HAS_KEXEC) += kimage.o obj-y += lib.o obj-y += memory.o obj-y += multicall.o diff --git a/xen/common/kimage.c b/xen/common/kimage.c new file mode 100644 index 0000000..6f5185c --- /dev/null +++ b/xen/common/kimage.c @@ -0,0 +1,842 @@ +/* + * Kexec Image + * + * Copyright (C) 2013 Citrix Systems R&D Ltd. + * + * Derived from kernel/kexec.c from Linux: + * + * Copyright (C) 2002-2004 Eric Biederman <ebiederm@xmission.com> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#include <xen/config.h> +#include <xen/types.h> +#include <xen/init.h> +#include <xen/kernel.h> +#include <xen/errno.h> +#include <xen/spinlock.h> +#include <xen/guest_access.h> +#include <xen/mm.h> +#include <xen/kexec.h> +#include <xen/kimage.h> + +#include <asm/page.h> + +/* + * When kexec transitions to the new kernel there is a one-to-one + * mapping between physical and virtual addresses. On processors + * where you can disable the MMU this is trivial, and easy. For + * others it is still a simple predictable page table to setup. + * + * In that environment kexec copies the new kernel to its final + * resting place. This means I can only support memory whose + * physical address can fit in an unsigned long. In particular + * addresses where (pfn << PAGE_SHIFT) > ULONG_MAX cannot be handled. + * If the assembly stub has more restrictive requirements + * KEXEC_SOURCE_MEMORY_LIMIT and KEXEC_DEST_MEMORY_LIMIT can be + * defined more restrictively in <asm/kexec.h>. + * + * The code for the transition from the current kernel to the + * the new kernel is placed in the control_code_buffer, whose size + * is given by KEXEC_CONTROL_PAGE_SIZE. In the best case only a single + * page of memory is necessary, but some architectures require more. + * Because this memory must be identity mapped in the transition from + * virtual to physical addresses it must live in the range + * 0 - TASK_SIZE, as only the user space mappings are arbitrarily + * modifiable. + * + * The assembly stub in the control code buffer is passed a linked list + * of descriptor pages detailing the source pages of the new kernel, + * and the destination addresses of those source pages. As this data + * structure is not used in the context of the current OS, it must + * be self-contained. + * + * The code has been made to work with highmem pages and will use a + * destination page in its final resting place (if it happens + * to allocate it). The end product of this is that most of the + * physical address space, and most of RAM can be used. + * + * Future directions include: + * - allocating a page table with the control code buffer identity + * mapped, to simplify machine_kexec and make kexec_on_panic more + * reliable. + */ + +/* + * KIMAGE_NO_DEST is an impossible destination address..., for + * allocating pages whose destination address we do not care about. + */ +#define KIMAGE_NO_DEST (-1UL) + +/* + * Offset of the last entry in an indirection page. + */ +#define KIMAGE_LAST_ENTRY (PAGE_SIZE/sizeof(kimage_entry_t) - 1) + + +static int kimage_is_destination_range(struct kexec_image *image, + unsigned long start, unsigned long end); +static struct page_info *kimage_alloc_page(struct kexec_image *image, + unsigned long dest); + +static struct page_info *kimage_alloc_zeroed_page(unsigned memflags) +{ + struct page_info *page; + + page = alloc_domheap_page(NULL, memflags); + if ( page == NULL ) + return NULL; + + clear_domain_page(page_to_mfn(page)); + + return page; +} + +static int do_kimage_alloc(struct kexec_image **rimage, unsigned long entry, + unsigned long nr_segments, + xen_kexec_segment_t *segments, uint8_t type) +{ + struct kexec_image *image; + unsigned long i; + int result; + + /* Allocate a controlling structure */ + result = -ENOMEM; + image = xzalloc(typeof(*image)); + if ( !image ) + goto out; + + image->control_page = ~0; /* By default this does not apply */ + image->entry_maddr = entry; + image->type = type; + image->nr_segments = nr_segments; + image->segments = segments; + + INIT_PAGE_LIST_HEAD(&image->control_pages); + INIT_PAGE_LIST_HEAD(&image->dest_pages); + INIT_PAGE_LIST_HEAD(&image->unuseable_pages); + + /* + * Verify we have good destination addresses. The caller is + * responsible for making certain we don't attempt to load + * the new image into invalid or reserved areas of RAM. This + * just verifies it is an address we can use. + * + * Since the kernel does everything in page size chunks ensure + * the destination addresses are page aligned. Too many + * special cases crop of when we don't do this. The most + * insidious is getting overlapping destination addresses + * simply because addresses are changed to page size + * granularity. + */ + result = -EADDRNOTAVAIL; + for ( i = 0; i < nr_segments; i++ ) + { + unsigned long mstart, mend; + + mstart = image->segments[i].dest_maddr; + mend = mstart + image->segments[i].dest_size; + if ( (mstart & ~PAGE_MASK) || (mend & ~PAGE_MASK) ) + goto out; + if ( mend >= KEXEC_DESTINATION_MEMORY_LIMIT ) + goto out; + } + + /* Verify our destination addresses do not overlap. + * If we allowed overlapping destination addresses + * through very weird things can happen with no + * easy explanation as one segment stops on another. + */ + result = -EINVAL; + for ( i = 0; i < nr_segments; i++ ) + { + unsigned long mstart, mend; + unsigned long j; + + mstart = image->segments[i].dest_maddr; + mend = mstart + image->segments[i].dest_size; + for (j = 0; j < i; j++ ) + { + unsigned long pstart, pend; + pstart = image->segments[j].dest_maddr; + pend = pstart + image->segments[j].dest_size; + /* Do the segments overlap ? */ + if ( (mend > pstart) && (mstart < pend) ) + goto out; + } + } + + /* Ensure our buffer sizes are strictly less than + * our memory sizes. This should always be the case, + * and it is easier to check up front than to be surprised + * later on. + */ + result = -EINVAL; + for ( i = 0; i < nr_segments; i++ ) + { + if ( image->segments[i].buf_size > image->segments[i].dest_size ) + goto out; + } + + /* Page for the relocation code must still be accessible after the + processor has switched to 32-bit mode. */ + result = -ENOMEM; + image->control_code_page = kimage_alloc_control_page(image, MEMF_bits(32)); + if ( !image->control_code_page ) + goto out; + + /* Add an empty indirection page. */ + image->entry_page = kimage_alloc_control_page(image, 0); + if ( !image->entry_page ) + goto out; + + image->head = page_to_maddr(image->entry_page); + image->next_entry = 0; + + result = 0; +out: + if ( result == 0 ) + *rimage = image; + else + kimage_free(image); + + return result; + +} + +static int kimage_normal_alloc(struct kexec_image **rimage, unsigned long entry, + unsigned long nr_segments, + xen_kexec_segment_t *segments) +{ + return do_kimage_alloc(rimage, entry, nr_segments, segments, + KEXEC_TYPE_DEFAULT); +} + +static int kimage_crash_alloc(struct kexec_image **rimage, unsigned long entry, + unsigned long nr_segments, + xen_kexec_segment_t *segments) +{ + unsigned long i; + int result; + + /* Verify we have a valid entry point */ + if ( (entry < kexec_crash_area.start) + || (entry > kexec_crash_area.start + kexec_crash_area.size)) + return -EADDRNOTAVAIL; + + /* + * Verify we have good destination addresses. Normally + * the caller is responsible for making certain we don't + * attempt to load the new image into invalid or reserved + * areas of RAM. But crash kernels are preloaded into a + * reserved area of ram. We must ensure the addresses + * are in the reserved area otherwise preloading the + * kernel could corrupt things. + */ + for ( i = 0; i < nr_segments; i++ ) + { + unsigned long mstart, mend; + + mstart = segments[i].dest_maddr; + mend = mstart + segments[i].dest_size - 1; + /* Ensure we are within the crash kernel limits */ + if ( (mstart < kexec_crash_area.start ) + || (mend > kexec_crash_area.start + kexec_crash_area.size)) + return -EADDRNOTAVAIL; + } + + /* Allocate and initialize a controlling structure */ + result = do_kimage_alloc(rimage, entry, nr_segments, segments, + KEXEC_TYPE_CRASH); + if ( result ) + return result; + + /* Enable the special crash kernel control page allocation + policy. */ + (*rimage)->control_page = kexec_crash_area.start; + + return 0; +} + +static int kimage_is_destination_range(struct kexec_image *image, + unsigned long start, + unsigned long end) +{ + unsigned long i; + + for ( i = 0; i < image->nr_segments; i++ ) + { + unsigned long mstart, mend; + + mstart = image->segments[i].dest_maddr; + mend = mstart + image->segments[i].dest_size; + if ( (end > mstart) && (start < mend) ) + return 1; + } + + return 0; +} + +static void kimage_free_page_list(struct page_list_head *list) +{ + struct page_info *page, *next; + + page_list_for_each_safe(page, next, list) + { + page_list_del(page, list); + free_domheap_page(page); + } +} + +static struct page_info *kimage_alloc_normal_control_page( + struct kexec_image *image, unsigned memflags) +{ + /* Control pages are special, they are the intermediaries + * that are needed while we copy the rest of the pages + * to their final resting place. As such they must + * not conflict with either the destination addresses + * or memory the kernel is already using. + * + * The only case where we really need more than one of + * these are for architectures where we cannot disable + * the MMU and must instead generate an identity mapped + * page table for all of the memory. + * + * At worst this runs in O(N) of the image size. + */ + struct page_list_head extra_pages; + struct page_info *page = NULL; + + INIT_PAGE_LIST_HEAD(&extra_pages); + + /* Loop while I can allocate a page and the page allocated + * is a destination page. + */ + do { + unsigned long mfn, emfn, addr, eaddr; + + page = kimage_alloc_zeroed_page(memflags); + if ( !page ) + break; + mfn = page_to_mfn(page); + emfn = mfn + 1; + addr = mfn << PAGE_SHIFT; + eaddr = emfn << PAGE_SHIFT; + if ( (emfn >= (KEXEC_CONTROL_MEMORY_LIMIT >> PAGE_SHIFT)) || + kimage_is_destination_range(image, addr, eaddr) ) + { + page_list_add(page, &extra_pages); + page = NULL; + } + } while ( !page ); + + if ( page ) + { + /* Remember the allocated page... */ + page_list_add(page, &image->control_pages); + + /* Because the page is already in it's destination + * location we will never allocate another page at + * that address. Therefore kimage_alloc_page + * will not return it (again) and we don't need + * to give it an entry in image->segments[]. + */ + } + /* Deal with the destination pages I have inadvertently allocated. + * + * Ideally I would convert multi-page allocations into single + * page allocations, and add everything to image->dest_pages. + * + * For now it is simpler to just free the pages. + */ + kimage_free_page_list(&extra_pages); + + return page; +} + +static struct page_info *kimage_alloc_crash_control_page(struct kexec_image *image) +{ + /* Control pages are special, they are the intermediaries + * that are needed while we copy the rest of the pages + * to their final resting place. As such they must + * not conflict with either the destination addresses + * or memory the kernel is already using. + * + * Control pages are also the only pags we must allocate + * when loading a crash kernel. All of the other pages + * are specified by the segments and we just memcpy + * into them directly. + * + * The only case where we really need more than one of + * these are for architectures where we cannot disable + * the MMU and must instead generate an identity mapped + * page table for all of the memory. + * + * Given the low demand this implements a very simple + * allocator that finds the first hole of the appropriate + * size in the reserved memory region, and allocates all + * of the memory up to and including the hole. + */ + unsigned long hole_start, hole_end, size; + struct page_info *page; + + page = NULL; + size = PAGE_SIZE; + hole_start = (image->control_page + (size - 1)) & ~(size - 1); + hole_end = hole_start + size - 1; + while ( hole_end <= kexec_crash_area.start + kexec_crash_area.size ) + { + unsigned long i; + + if ( hole_end > KEXEC_CRASH_CONTROL_MEMORY_LIMIT ) + break; + if ( hole_end > kexec_crash_area.start + kexec_crash_area.size ) + break; + /* See if I overlap any of the segments */ + for ( i = 0; i < image->nr_segments; i++ ) + { + unsigned long mstart, mend; + + mstart = image->segments[i].dest_maddr; + mend = mstart + image->segments[i].dest_size - 1; + if ( (hole_end >= mstart) && (hole_start <= mend) ) + { + /* Advance the hole to the end of the segment */ + hole_start = (mend + (size - 1)) & ~(size - 1); + hole_end = hole_start + size - 1; + break; + } + } + /* If I don't overlap any segments I have found my hole! */ + if ( i == image->nr_segments ) + { + page = mfn_to_page(hole_start >> PAGE_SHIFT); + break; + } + } + if ( page ) + { + image->control_page = hole_end; + clear_domain_page(page_to_mfn(page)); + } + + return page; +} + + +struct page_info *kimage_alloc_control_page(struct kexec_image *image, + unsigned memflags) +{ + struct page_info *pages = NULL; + + switch ( image->type ) + { + case KEXEC_TYPE_DEFAULT: + pages = kimage_alloc_normal_control_page(image, memflags); + break; + case KEXEC_TYPE_CRASH: + pages = kimage_alloc_crash_control_page(image); + break; + } + return pages; +} + +static int kimage_add_entry(struct kexec_image *image, kimage_entry_t entry) +{ + kimage_entry_t *entries; + + if ( image->next_entry == KIMAGE_LAST_ENTRY ) + { + struct page_info *page; + + page = kimage_alloc_page(image, KIMAGE_NO_DEST); + if ( !page ) + return -ENOMEM; + + entries = __map_domain_page(image->entry_page); + entries[image->next_entry] = page_to_maddr(page) | IND_INDIRECTION; + unmap_domain_page(entries); + + image->entry_page = page; + image->next_entry = 0; + } + + entries = __map_domain_page(image->entry_page); + entries[image->next_entry] = entry; + image->next_entry++; + entries[image->next_entry] = 0; + unmap_domain_page(entries); + + + return 0; +} + +static int kimage_set_destination(struct kexec_image *image, + unsigned long destination) +{ + return kimage_add_entry(image, (destination & PAGE_MASK) | IND_DESTINATION); +} + + +static int kimage_add_page(struct kexec_image *image, unsigned long page) +{ + return kimage_add_entry(image, (page & PAGE_MASK) | IND_SOURCE); +} + + +static void kimage_free_extra_pages(struct kexec_image *image) +{ + kimage_free_page_list(&image->dest_pages); + kimage_free_page_list(&image->unuseable_pages); + +} + +static void kimage_terminate(struct kexec_image *image) +{ + kimage_entry_t *entries; + + entries = __map_domain_page(image->entry_page); + entries[image->next_entry] = IND_DONE; + unmap_domain_page(entries); +} + +/* + * Iterate over all the entries in the indirection pages. + * + * Call unmap_domain_page(ptr) after the loop exits. + */ +#define for_each_kimage_entry(image, ptr, entry) \ + for ( ptr = map_domain_page(image->head >> PAGE_SHIFT); \ + (entry = *ptr) && !(entry & IND_DONE); \ + ptr = (entry & IND_INDIRECTION) ? \ + (unmap_domain_page(ptr), map_domain_page(entry >> PAGE_SHIFT)) \ + : ptr + 1 ) + +static void kimage_free_entry(kimage_entry_t entry) +{ + struct page_info *page; + + page = mfn_to_page(entry >> PAGE_SHIFT); + free_domheap_page(page); +} + +void kimage_free(struct kexec_image *image) +{ + kimage_entry_t *ptr, entry; + kimage_entry_t ind = 0; + + if ( !image ) + return; + + kimage_free_extra_pages(image); + for_each_kimage_entry(image, ptr, entry) + { + if ( entry & IND_INDIRECTION ) + { + /* Free the previous indirection page */ + if ( ind & IND_INDIRECTION ) + kimage_free_entry(ind); + /* Save this indirection page until we are + * done with it. + */ + ind = entry; + } + else if ( entry & IND_SOURCE ) + kimage_free_entry(entry); + } + unmap_domain_page(ptr); + + /* Free the final indirection page */ + if ( ind & IND_INDIRECTION ) + kimage_free_entry(ind); + + /* Free the kexec control pages... */ + kimage_free_page_list(&image->control_pages); + xfree(image->segments); + xfree(image); +} + +static kimage_entry_t *kimage_dst_used(struct kexec_image *image, + unsigned long page) +{ + kimage_entry_t *ptr, entry; + unsigned long destination = 0; + + for_each_kimage_entry(image, ptr, entry) + { + if ( entry & IND_DESTINATION ) + destination = entry & PAGE_MASK; + else if ( entry & IND_SOURCE ) + { + if ( page == destination ) + return ptr; + destination += PAGE_SIZE; + } + } + unmap_domain_page(ptr); + + return NULL; +} + +static struct page_info *kimage_alloc_page(struct kexec_image *image, + unsigned long destination) +{ + /* + * Here we implement safeguards to ensure that a source page + * is not copied to its destination page before the data on + * the destination page is no longer useful. + * + * To do this we maintain the invariant that a source page is + * either its own destination page, or it is not a + * destination page at all. + * + * That is slightly stronger than required, but the proof + * that no problems will not occur is trivial, and the + * implementation is simply to verify. + * + * When allocating all pages normally this algorithm will run + * in O(N) time, but in the worst case it will run in O(N^2) + * time. If the runtime is a problem the data structures can + * be fixed. + */ + struct page_info *page; + unsigned long addr; + + /* + * Walk through the list of destination pages, and see if I + * have a match. + */ + page_list_for_each(page, &image->dest_pages) + { + addr = page_to_mfn(page) << PAGE_SHIFT; + if ( addr == destination ) + { + page_list_del(page, &image->dest_pages); + return page; + } + } + page = NULL; + for (;;) + { + kimage_entry_t *old; + + /* Allocate a page, if we run out of memory give up */ + page = kimage_alloc_zeroed_page(0); + if ( !page ) + return NULL; + /* If the page cannot be used file it away */ + if ( page_to_mfn(page) > + (KEXEC_SOURCE_MEMORY_LIMIT >> PAGE_SHIFT) ) + { + page_list_add(page, &image->unuseable_pages); + continue; + } + addr = page_to_mfn(page) << PAGE_SHIFT; + + /* If it is the destination page we want use it */ + if ( addr == destination ) + break; + + /* If the page is not a destination page use it */ + if ( !kimage_is_destination_range(image, addr, + addr + PAGE_SIZE) ) + break; + + /* + * I know that the page is someones destination page. + * See if there is already a source page for this + * destination page. And if so swap the source pages. + */ + old = kimage_dst_used(image, addr); + if ( old ) + { + /* If so move it */ + unsigned long old_mfn = *old >> PAGE_SHIFT; + unsigned long mfn = addr >> PAGE_SHIFT; + + copy_domain_page(mfn, old_mfn); + *old = (addr & ~PAGE_MASK) | IND_SOURCE; + unmap_domain_page(old); + + page = mfn_to_page(old_mfn); + break; + } + else + { + /* Place the page on the destination list I + * will use it later. + */ + page_list_add(page, &image->dest_pages); + } + } + + return page; +} + +static int kimage_load_normal_segment(struct kexec_image *image, + xen_kexec_segment_t *segment) +{ + unsigned long to_copy; + unsigned long src_offset; + unsigned long dest; + int ret; + + to_copy = segment->buf_size; + src_offset = 0; + dest = segment->dest_maddr; + + ret = kimage_set_destination(image, dest); + if ( ret < 0 ) + return ret; + + while ( to_copy ) + { + unsigned long dest_mfn; + size_t dest_off; + struct page_info *page; + void *dest_va; + size_t size; + + dest_mfn = dest >> PAGE_SHIFT; + dest_off = dest & ~PAGE_MASK; + + size = min(PAGE_SIZE - dest_off, to_copy); + + page = kimage_alloc_page(image, dest); + if ( !page ) + return -ENOMEM; + ret = kimage_add_page(image, page_to_mfn(page) << PAGE_SHIFT); + if ( ret < 0 ) + return ret; + + dest_va = __map_domain_page(page); + ret = copy_from_guest_offset(dest_va + dest_off, segment->buf, src_offset, size); + unmap_domain_page(dest_va); + if ( ret ) + return -EFAULT; + + to_copy -= size; + src_offset += size; + dest += size; + } + + return 0; +} + +static int kimage_load_crash_segment(struct kexec_image *image, + xen_kexec_segment_t *segment) +{ + /* For crash dumps kernels we simply copy the data from + * user space to it's destination. + * We do things a page at a time for the sake of kmap. + */ + unsigned long dest; + unsigned long sbytes, dbytes; + int ret = 0; + unsigned long src_offset = 0; + + sbytes = segment->buf_size; + dbytes = segment->dest_size; + dest = segment->dest_maddr; + + while ( dbytes ) + { + unsigned long dest_mfn; + size_t dest_off; + void *dest_va; + size_t schunk, dchunk; + + dest_mfn = dest >> PAGE_SHIFT; + dest_off = dest & ~PAGE_MASK; + + dchunk = min(PAGE_SIZE - dest_off, dbytes); + schunk = min(dchunk, sbytes); + + dest_va = map_domain_page(dest_mfn); + if ( dest_va == NULL ) + return -EINVAL; + + ret = copy_from_guest_offset(dest_va + dest_off, segment->buf, src_offset, schunk); + memset(dest_va + dest_off + schunk, 0, dchunk - schunk); + + unmap_domain_page(dest_va); + if ( ret ) + return -EFAULT; + + dbytes -= dchunk; + sbytes -= schunk; + dest += dchunk; + src_offset += schunk; + } + + return 0; +} + +static int kimage_load_segment(struct kexec_image *image, xen_kexec_segment_t *segment) +{ + int result = -ENOMEM; + + switch ( image->type ) + { + case KEXEC_TYPE_DEFAULT: + result = kimage_load_normal_segment(image, segment); + break; + case KEXEC_TYPE_CRASH: + result = kimage_load_crash_segment(image, segment); + break; + } + + return result; +} + +int kimage_alloc(struct kexec_image **rimage, uint8_t type, uint16_t arch, + uint64_t entry_maddr, + uint32_t nr_segments, xen_kexec_segment_t *segment) +{ + int result; + + switch( type ) + { + case KEXEC_TYPE_DEFAULT: + result = kimage_normal_alloc(rimage, entry_maddr, nr_segments, segment); + break; + case KEXEC_TYPE_CRASH: + result = kimage_crash_alloc(rimage, entry_maddr, nr_segments, segment); + break; + default: + result = -EINVAL; + break; + } + if ( result < 0 ) + return result; + + (*rimage)->arch = arch; + + return result; +} + +int kimage_load_segments(struct kexec_image *image) +{ + int s; + int result; + + for ( s = 0; s < image->nr_segments; s++ ) { + result = kimage_load_segment(image, &image->segments[s]); + if ( result < 0 ) + return result; + } + kimage_terminate(image); + return 0; +} + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ diff --git a/xen/include/xen/kimage.h b/xen/include/xen/kimage.h new file mode 100644 index 0000000..9a785a1 --- /dev/null +++ b/xen/include/xen/kimage.h @@ -0,0 +1,63 @@ +#ifndef __XEN_KIMAGE_H__ +#define __XEN_KIMAGE_H__ + +#include <xen/list.h> +#include <xen/mm.h> +#include <public/kexec.h> + +#define KEXEC_DESTINATION_MEMORY_LIMIT (~0ul) +#define KEXEC_CONTROL_MEMORY_LIMIT (~0ul) +#define KEXEC_CRASH_CONTROL_MEMORY_LIMIT (~0ul) +#define KEXEC_SOURCE_MEMORY_LIMIT (~0ul) + +#define KEXEC_CONTROL_PAGE_SIZE PAGE_SIZE + +#define KEXEC_SEGMENT_MAX 16 + +typedef unsigned long kimage_entry_t; +#define IND_DESTINATION 0x1 +#define IND_INDIRECTION 0x2 +#define IND_DONE 0x4 +#define IND_SOURCE 0x8 + +struct kexec_image { + uint8_t type; + uint16_t arch; + uint64_t entry_maddr; + uint32_t nr_segments; + xen_kexec_segment_t *segments; + + kimage_entry_t head; + struct page_info *entry_page; + unsigned next_entry; + + struct page_info *control_code_page; + struct page_info *aux_page; + + struct page_list_head control_pages; + struct page_list_head dest_pages; + struct page_list_head unuseable_pages; + + /* Address of next control page to allocate for crash kernels. */ + unsigned long control_page; +}; + +int kimage_alloc(struct kexec_image **rimage, uint8_t type, uint16_t arch, + uint64_t entry_maddr, + uint32_t nr_segments, xen_kexec_segment_t *segment); +void kimage_free(struct kexec_image *image); +int kimage_load_segments(struct kexec_image *image); +struct page_info *kimage_alloc_control_page(struct kexec_image *image, + unsigned memflags); + +#endif /* __XEN_KIMAGE_H__ */ + +/* + * Local variables: + * mode: C + * c-file-style: "BSD" + * c-basic-offset: 4 + * tab-width: 4 + * indent-tabs-mode: nil + * End: + */ -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* Re: [Xen-devel] [PATCH 4/8] kexec: add infrastructure for handling kexec images 2013-04-08 18:59 ` [PATCH 4/8] kexec: add infrastructure for handling kexec images David Vrabel @ 2013-04-09 7:44 ` Jan Beulich 2013-04-09 16:17 ` David Vrabel 0 siblings, 1 reply; 34+ messages in thread From: Jan Beulich @ 2013-04-09 7:44 UTC (permalink / raw) To: David Vrabel, xen-devel; +Cc: kexec, Daniel Kiper, Ian Jackson, Ian Campbell >>> On 08.04.13 at 20:59, David Vrabel <david.vrabel@citrix.com> wrote: > + ret = kimage_add_page(image, page_to_mfn(page) << PAGE_SHIFT); Constructs like this aren't portable. You ought to use page_to_maddr(), and have the called function have paddr_t instead of unsigned long as the respective parameter. > + struct page_list_head unuseable_pages; unusable_pages. Also there appear to be a few hard tabs here and there. Jan _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [Xen-devel] [PATCH 4/8] kexec: add infrastructure for handling kexec images 2013-04-09 7:44 ` [Xen-devel] " Jan Beulich @ 2013-04-09 16:17 ` David Vrabel 2013-04-10 8:36 ` Jan Beulich 0 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-09 16:17 UTC (permalink / raw) To: Jan Beulich Cc: kexec@lists.infradead.org, Daniel Kiper, Ian Jackson, Ian Campbell, xen-devel@lists.xen.org On 09/04/13 08:44, Jan Beulich wrote: >>>> On 08.04.13 at 20:59, David Vrabel <david.vrabel@citrix.com> wrote: >> + ret = kimage_add_page(image, page_to_mfn(page) << PAGE_SHIFT); > > Constructs like this aren't portable. You ought to use > page_to_maddr(), and have the called function have paddr_t > instead of unsigned long as the respective parameter. I will make this change but it isn't clear to me why this isn't portable. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [Xen-devel] [PATCH 4/8] kexec: add infrastructure for handling kexec images 2013-04-09 16:17 ` David Vrabel @ 2013-04-10 8:36 ` Jan Beulich 0 siblings, 0 replies; 34+ messages in thread From: Jan Beulich @ 2013-04-10 8:36 UTC (permalink / raw) To: David Vrabel Cc: kexec@lists.infradead.org, Daniel Kiper, Ian Jackson, Ian Campbell, xen-devel@lists.xen.org >>> On 09.04.13 at 18:17, David Vrabel <david.vrabel@citrix.com> wrote: > On 09/04/13 08:44, Jan Beulich wrote: >>>>> On 08.04.13 at 20:59, David Vrabel <david.vrabel@citrix.com> wrote: >>> + ret = kimage_add_page(image, page_to_mfn(page) << PAGE_SHIFT); >> >> Constructs like this aren't portable. You ought to use >> page_to_maddr(), and have the called function have paddr_t >> instead of unsigned long as the respective parameter. > > I will make this change but it isn't clear to me why this isn't portable. Because left shifting an unsigned long may shift out significant bits, namely on 32-bit architectures (and the code here is - iirc - living under xen/common/). Jan _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel ` (3 preceding siblings ...) 2013-04-08 18:59 ` [PATCH 4/8] kexec: add infrastructure for handling kexec images David Vrabel @ 2013-04-08 18:59 ` David Vrabel 2013-04-09 21:02 ` Daniel Kiper 2013-04-08 18:59 ` [PATCH 6/8] xen: kexec crash image when dom0 crashes David Vrabel ` (2 subsequent siblings) 7 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw) To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell From: David Vrabel <david.vrabel@citrix.com> In the existing kexec hypercall, the load and unload ops depend on internals of the Linux kernel (the page list and code page provided by the kernel). The code page is used to transition between Xen context and the image so using kernel code doesn't make sense and will not work for PVH guests. Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops that no longer require a code page to be provided by the guest -- Xen now provides the code for calling the image directly. The new load op looks similar to the Linux kexec_load system call and allows the guest to provide the image data to be loaded. The guest specifies the architecture of the image which may be a 32-bit subarch of the hypervisor's architecture (i.e., an EM_386 image on an EM_X86_64 hypervisor). The toolstack can now load images without kernel involvement. This is required for supporting kexec when using a dom0 with an upstream kernel. Crash images are copied directly into the crash region on load. Default images are copied into domheap pages and a list of source and destination machine addresses is created. This is list is used in kexec_reloc() to relocate the image to its destination. The old load and unload sub-ops are still available (as KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top of the new infrastructure. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- xen/arch/x86/machine_kexec.c | 282 +++++++++++++++++++------ xen/arch/x86/x86_64/Makefile | 2 +- xen/arch/x86/x86_64/compat_kexec.S | 187 ---------------- xen/arch/x86/x86_64/kexec_reloc.S | 215 +++++++++++++++++++ xen/common/kexec.c | 397 +++++++++++++++++++++++++++++------ xen/common/kimage.c | 78 +++++++ xen/include/asm-x86/fixmap.h | 3 - xen/include/asm-x86/machine_kexec.h | 14 ++ xen/include/xen/kexec.h | 14 +- xen/include/xen/kimage.h | 6 + 10 files changed, 866 insertions(+), 332 deletions(-) delete mode 100644 xen/arch/x86/x86_64/compat_kexec.S create mode 100644 xen/arch/x86/x86_64/kexec_reloc.S create mode 100644 xen/include/asm-x86/machine_kexec.h diff --git a/xen/arch/x86/machine_kexec.c b/xen/arch/x86/machine_kexec.c index 68b9705..e6c34c5 100644 --- a/xen/arch/x86/machine_kexec.c +++ b/xen/arch/x86/machine_kexec.c @@ -1,9 +1,18 @@ /****************************************************************************** * machine_kexec.c * + * Copyright (C) 2013 Citrix Systems R&D Ltd. + * + * Portions derived from Linux's arch/x86/kernel/machine_kexec_64.c. + * + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> + * * Xen port written by: * - Simon 'Horms' Horman <horms@verge.net.au> * - Magnus Damm <magnus@valinux.co.jp> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. */ #include <xen/types.h> @@ -11,63 +20,216 @@ #include <xen/guest_access.h> #include <asm/fixmap.h> #include <asm/hpet.h> +#include <asm/page.h> +#include <asm/machine_kexec.h> + +static void init_level2_page(l2_pgentry_t *l2, unsigned long addr) +{ + unsigned long end_addr; + + addr &= PAGE_MASK; + end_addr = addr + L2_PAGETABLE_ENTRIES * (1ul << L2_PAGETABLE_SHIFT); -typedef void (*relocate_new_kernel_t)( - unsigned long indirection_page, - unsigned long *page_list, - unsigned long start_address, - unsigned int preserve_context); + while ( addr < end_addr ) + { + l2e_write(l2++, l2e_from_paddr(addr, __PAGE_HYPERVISOR | _PAGE_PSE)); -int machine_kexec_load(int type, int slot, xen_kexec_image_t *image) + addr += 1ul << L2_PAGETABLE_SHIFT; + } +} + +static int init_level3_page(struct kexec_image *image, l3_pgentry_t *l3, + unsigned long addr, unsigned long last_addr) { - unsigned long prev_ma = 0; - int fix_base = FIX_KEXEC_BASE_0 + (slot * (KEXEC_XEN_NO_PAGES >> 1)); - int k; + unsigned long end_addr; - /* setup fixmap to point to our pages and record the virtual address - * in every odd index in page_list[]. - */ + addr &= PAGE_MASK; + end_addr = addr + L3_PAGETABLE_ENTRIES * (1ul << L3_PAGETABLE_SHIFT); - for ( k = 0; k < KEXEC_XEN_NO_PAGES; k++ ) + while( (addr < last_addr) && (addr < end_addr) ) { - if ( (k & 1) == 0 ) - { - /* Even pages: machine address. */ - prev_ma = image->page_list[k]; - } - else - { - /* Odd pages: va for previous ma. */ - if ( is_pv_32on64_domain(dom0) ) - { - /* - * The compatability bounce code sets up a page table - * with a 1-1 mapping of the first 1G of memory so - * VA==PA here. - * - * This Linux purgatory code still sets up separate - * high and low mappings on the control page (entries - * 0 and 1) but it is harmless if they are equal since - * that PT is not live at the time. - */ - image->page_list[k] = prev_ma; - } - else - { - set_fixmap(fix_base + (k >> 1), prev_ma); - image->page_list[k] = fix_to_virt(fix_base + (k >> 1)); - } - } + struct page_info *l2_page; + l2_pgentry_t *l2; + + l2_page = kimage_alloc_control_page(image, 0); + if ( !l2_page ) + return -ENOMEM; + l2 = __map_domain_page(l2_page); + init_level2_page(l2, addr); + unmap_domain_page(l2); + + l3e_write(l3++, l3e_from_page(l2_page, __PAGE_HYPERVISOR)); + + addr += 1ul << L3_PAGETABLE_SHIFT; } return 0; } -void machine_kexec_unload(int type, int slot, xen_kexec_image_t *image) +/* + * Build a complete page table to identity map [addr, last_addr). + * + * Control pages are used so they do not overlap with the image source + * or destination. + */ +static int init_level4_page(struct kexec_image *image, l4_pgentry_t *l4, + unsigned long addr, unsigned long last_addr) { + unsigned long end_addr; + int result; + + addr &= PAGE_MASK; + end_addr = addr + L4_PAGETABLE_ENTRIES * (1ul << L4_PAGETABLE_SHIFT); + + while ( (addr < last_addr) && (addr < end_addr) ) + { + struct page_info *l3_page; + l3_pgentry_t *l3; + + l3_page = kimage_alloc_control_page(image, 0); + if ( !l3_page ) + return -ENOMEM; + l3 = __map_domain_page(l3_page); + result = init_level3_page(image, l3, addr, last_addr); + unmap_domain_page(l3); + if (result) + return result; + + l4e_write(l4++, l4e_from_page(l3_page, __PAGE_HYPERVISOR)); + + addr += 1ul << L4_PAGETABLE_SHIFT; + } + + return 0; } -void machine_reboot_kexec(xen_kexec_image_t *image) +/* + * Add a mapping for the control code page to the same virtual address + * as kexec_reloc. This allows us to keep running after these page + * tables are loaded in kexec_reloc. + * + * We don't really need to allocate control pages here as these + * entries won't be used while the kexec image is being copied, but it + * makes clean-up easier. + */ +static int init_transition_pgtable(struct kexec_image *image, l4_pgentry_t *l4) +{ + struct page_info *l3_page; + struct page_info *l2_page; + struct page_info *l1_page; + unsigned long vaddr, paddr; + l3_pgentry_t *l3 = NULL; + l2_pgentry_t *l2 = NULL; + l1_pgentry_t *l1 = NULL; + int ret = -ENOMEM; + + vaddr = (unsigned long)kexec_reloc; + paddr = page_to_maddr(image->control_code_page); + + l4 += l4_table_offset(vaddr); + if ( !(l4e_get_flags(*l4) & _PAGE_PRESENT) ) + { + l3_page = kimage_alloc_control_page(image, 0); + if ( !l3_page ) + goto out; + l4e_write(l4, l4e_from_page(l3_page, __PAGE_HYPERVISOR)); + } + else + l3_page = l4e_get_page(*l4); + + l3 = __map_domain_page(l3_page); + l3 += l3_table_offset(vaddr); + if ( !(l3e_get_flags(*l3) & _PAGE_PRESENT) ) + { + l2_page = kimage_alloc_control_page(image, 0); + if ( !l2_page ) + goto out; + l3e_write(l3, l3e_from_page(l2_page, __PAGE_HYPERVISOR)); + } + else + l2_page = l3e_get_page(*l3); + + l2 = __map_domain_page(l2_page); + l2 += l2_table_offset(vaddr); + if ( !(l2e_get_flags(*l2) & _PAGE_PRESENT) ) + { + l1_page = kimage_alloc_control_page(image, 0); + if ( !l1_page ) + goto out; + l2e_write(l2, l2e_from_page(l1_page, __PAGE_HYPERVISOR)); + } + else + l1_page = l2e_get_page(*l2); + + l1 = __map_domain_page(l1_page); + l1 += l1_table_offset(vaddr); + l1e_write(l1, l1e_from_pfn(paddr >> PAGE_SHIFT, __PAGE_HYPERVISOR)); + + ret = 0; +out: + if ( l1 ) + unmap_domain_page(l1); + if ( l2 ) + unmap_domain_page(l2); + if ( l3 ) + unmap_domain_page(l3); + return ret; +} + + +static int build_reloc_page_table(struct kexec_image *image) +{ + struct page_info *l4_page; + l4_pgentry_t *l4; + int result; + + l4_page = kimage_alloc_control_page(image, 0); + if ( !l4_page ) + return -ENOMEM; + l4 = __map_domain_page(l4_page); + + result = init_level4_page(image, l4, 0, max_page << PAGE_SHIFT); + if ( result == 0) + result = init_transition_pgtable(image, l4); + unmap_domain_page(l4); + if ( result ) + return result; + + image->aux_page = l4_page; + return 0; +} + +int machine_kexec_load(struct kexec_image *image) +{ + void *code_page; + int ret; + + switch ( image->arch ) + { + case EM_386: + case EM_X86_64: + break; + default: + return -EINVAL; + } + + code_page = __map_domain_page(image->control_code_page); + memcpy(code_page, kexec_reloc, PAGE_SIZE); + unmap_domain_page(code_page); + + ret = build_reloc_page_table(image); + if ( ret < 0 ) + return ret; + + return 0; +} + +void machine_kexec_unload(struct kexec_image *image) +{ + /* no-op. kimage_free() frees all control pages. */ +} + +void machine_reboot_kexec(struct kexec_image *image) { BUG_ON(smp_processor_id() != 0); smp_send_stop(); @@ -75,13 +237,10 @@ void machine_reboot_kexec(xen_kexec_image_t *image) BUG(); } -void machine_kexec(xen_kexec_image_t *image) +void machine_kexec(struct kexec_image *image) { - struct desc_ptr gdt_desc = { - .base = (unsigned long)(boot_cpu_gdt_table - FIRST_RESERVED_GDT_ENTRY), - .limit = LAST_RESERVED_GDT_BYTE - }; int i; + unsigned long reloc_flags = 0; /* We are about to permenantly jump out of the Xen context into the kexec * purgatory code. We really dont want to be still servicing interupts. @@ -109,29 +268,12 @@ void machine_kexec(xen_kexec_image_t *image) * not like running with NMIs disabled. */ enable_nmis(); - /* - * compat_machine_kexec() returns to idle pagetables, which requires us - * to be running on a static GDT mapping (idle pagetables have no GDT - * mappings in their per-domain mapping area). - */ - asm volatile ( "lgdt %0" : : "m" (gdt_desc) ); + if ( image->arch == EM_386 ) + reloc_flags |= KEXEC_RELOC_FLAG_COMPAT; - if ( is_pv_32on64_domain(dom0) ) - { - compat_machine_kexec(image->page_list[1], - image->indirection_page, - image->page_list, - image->start_address); - } - else - { - relocate_new_kernel_t rnk; - - rnk = (relocate_new_kernel_t) image->page_list[1]; - (*rnk)(image->indirection_page, image->page_list, - image->start_address, - 0 /* preserve_context */); - } + kexec_reloc(page_to_maddr(image->control_code_page), + page_to_maddr(image->aux_page), + image->head, image->entry_maddr, reloc_flags); } int machine_kexec_get(xen_kexec_range_t *range) diff --git a/xen/arch/x86/x86_64/Makefile b/xen/arch/x86/x86_64/Makefile index d56e12d..7f8fb3d 100644 --- a/xen/arch/x86/x86_64/Makefile +++ b/xen/arch/x86/x86_64/Makefile @@ -11,11 +11,11 @@ obj-y += mmconf-fam10h.o obj-y += mmconfig_64.o obj-y += mmconfig-shared.o obj-y += compat.o -obj-bin-y += compat_kexec.o obj-y += domain.o obj-y += physdev.o obj-y += platform_hypercall.o obj-y += cpu_idle.o obj-y += cpufreq.o +obj-bin-y += kexec_reloc.o obj-$(crash_debug) += gdbstub.o diff --git a/xen/arch/x86/x86_64/compat_kexec.S b/xen/arch/x86/x86_64/compat_kexec.S deleted file mode 100644 index fc92af9..0000000 --- a/xen/arch/x86/x86_64/compat_kexec.S +++ /dev/null @@ -1,187 +0,0 @@ -/* - * Compatibility kexec handler. - */ - -/* - * NOTE: We rely on Xen not relocating itself above the 4G boundary. This is - * currently true but if it ever changes then compat_pg_table will - * need to be moved back below 4G at run time. - */ - -#include <xen/config.h> - -#include <asm/asm_defns.h> -#include <asm/msr.h> -#include <asm/page.h> - -/* The unrelocated physical address of a symbol. */ -#define SYM_PHYS(sym) ((sym) - __XEN_VIRT_START) - -/* Load physical address of symbol into register and relocate it. */ -#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ - add xen_phys_start(%rip), reg - -/* - * Relocate a physical address in memory. Size of temporary register - * determines size of the value to relocate. - */ -#define RELOCATE_MEM(addr,reg) mov addr(%rip), reg ; \ - add xen_phys_start(%rip), reg ; \ - mov reg, addr(%rip) - - .text - - .code64 - -ENTRY(compat_machine_kexec) - /* x86/64 x86/32 */ - /* %rdi - relocate_new_kernel_t CALL */ - /* %rsi - indirection page 4(%esp) */ - /* %rdx - page_list 8(%esp) */ - /* %rcx - start address 12(%esp) */ - /* cpu has pae 16(%esp) */ - - /* Shim the 64 bit page_list into a 32 bit page_list. */ - mov $12,%r9 - lea compat_page_list(%rip), %rbx -1: dec %r9 - movl (%rdx,%r9,8),%eax - movl %eax,(%rbx,%r9,4) - test %r9,%r9 - jnz 1b - - RELOCATE_SYM(compat_page_list,%rdx) - - /* Relocate compatibility mode entry point address. */ - RELOCATE_MEM(compatibility_mode_far,%eax) - - /* Relocate compat_pg_table. */ - RELOCATE_MEM(compat_pg_table, %rax) - RELOCATE_MEM(compat_pg_table+0x8, %rax) - RELOCATE_MEM(compat_pg_table+0x10,%rax) - RELOCATE_MEM(compat_pg_table+0x18,%rax) - - /* - * Setup an identity mapped region in PML4[0] of idle page - * table. - */ - RELOCATE_SYM(l3_identmap,%rax) - or $0x63,%rax - mov %rax, idle_pg_table(%rip) - - /* Switch to idle page table. */ - RELOCATE_SYM(idle_pg_table,%rax) - movq %rax, %cr3 - - /* Switch to identity mapped compatibility stack. */ - RELOCATE_SYM(compat_stack,%rax) - movq %rax, %rsp - - /* Save xen_phys_start for 32 bit code. */ - movq xen_phys_start(%rip), %rbx - - /* Jump to low identity mapping in compatibility mode. */ - ljmp *compatibility_mode_far(%rip) - ud2 - -compatibility_mode_far: - .long SYM_PHYS(compatibility_mode) - .long __HYPERVISOR_CS32 - - /* - * We use 5 words of stack for the arguments passed to the kernel. The - * kernel only uses 1 word before switching to its own stack. Allocate - * 16 words to give "plenty" of room. - */ - .fill 16,4,0 -compat_stack: - - .code32 - -#undef RELOCATE_SYM -#undef RELOCATE_MEM - -/* - * Load physical address of symbol into register and relocate it. %rbx - * contains xen_phys_start(%rip) saved before jump to compatibility - * mode. - */ -#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ - add %ebx, reg - -compatibility_mode: - /* Setup some sane segments. */ - movl $__HYPERVISOR_DS32, %eax - movl %eax, %ds - movl %eax, %es - movl %eax, %fs - movl %eax, %gs - movl %eax, %ss - - /* Push arguments onto stack. */ - pushl $0 /* 20(%esp) - preserve context */ - pushl $1 /* 16(%esp) - cpu has pae */ - pushl %ecx /* 12(%esp) - start address */ - pushl %edx /* 8(%esp) - page list */ - pushl %esi /* 4(%esp) - indirection page */ - pushl %edi /* 0(%esp) - CALL */ - - /* Disable paging and therefore leave 64 bit mode. */ - movl %cr0, %eax - andl $~X86_CR0_PG, %eax - movl %eax, %cr0 - - /* Switch to 32 bit page table. */ - RELOCATE_SYM(compat_pg_table, %eax) - movl %eax, %cr3 - - /* Clear MSR_EFER[LME], disabling long mode */ - movl $MSR_EFER,%ecx - rdmsr - btcl $_EFER_LME,%eax - wrmsr - - /* Re-enable paging, but only 32 bit mode now. */ - movl %cr0, %eax - orl $X86_CR0_PG, %eax - movl %eax, %cr0 - jmp 1f -1: - - popl %eax - call *%eax - ud2 - - .data - .align 4 -compat_page_list: - .fill 12,4,0 - - .align 32,0 - - /* - * These compat page tables contain an identity mapping of the - * first 4G of the physical address space. - */ -compat_pg_table: - .long SYM_PHYS(compat_pg_table_l2) + 0*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 1*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 2*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 3*PAGE_SIZE + 0x01, 0 - - .section .data.page_aligned, "aw", @progbits - .align PAGE_SIZE,0 -compat_pg_table_l2: - .macro identmap from=0, count=512 - .if \count-1 - identmap "(\from+0)","(\count/2)" - identmap "(\from+(0x200000*(\count/2)))","(\count/2)" - .else - .quad 0x00000000000000e3 + \from - .endif - .endm - - identmap 0x00000000 - identmap 0x40000000 - identmap 0x80000000 - identmap 0xc0000000 diff --git a/xen/arch/x86/x86_64/kexec_reloc.S b/xen/arch/x86/x86_64/kexec_reloc.S new file mode 100644 index 0000000..9d09c35 --- /dev/null +++ b/xen/arch/x86/x86_64/kexec_reloc.S @@ -0,0 +1,215 @@ +/* + * Relocate a kexec_image to its destination and call it. + * + * Copyright (C) 2013 Citrix Systems R&D Ltd. + * + * Portions derived from Linux's arch/x86/kernel/relocate_kernel_64.S. + * + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ +#include <xen/config.h> + +#include <asm/asm_defns.h> +#include <asm/msr.h> +#include <asm/page.h> +#include <asm/machine_kexec.h> + +/* The unrelocated physical address of a symbol. */ +#define SYM_PHYS(sym) ((sym) - __XEN_VIRT_START) + +/* Load physical address of symbol into register and relocate it. */ +#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ + add xen_phys_start(%rip), reg + + .text + .align PAGE_SIZE + .code64 + +ENTRY(kexec_reloc) + /* %rdi - code_page maddr */ + /* %rsi - page table maddr */ + /* %rdx - indirection page maddr */ + /* %rcx - entry maddr */ + /* %r8 - flags */ + + mov %rdx, %rbx + + /* Setup stack. */ + RELOCATE_SYM(reloc_stack, %rax) + mov %rax, %rsp + + /* Load reloc page table. */ + movq %rsi, %cr3 + + /* Jump to identity mapped code. */ + movq %rdi, %r9 + addq $(identity_mapped - kexec_reloc), %r9 + + jmp *%r9 + +identity_mapped: + pushq %rcx + pushq %rbx + pushq %rsi + pushq %rdi + + /* + * Set cr0 to a known state: + * - Paging enabled + * - Alignment check disabled + * - Write protect disabled + * - No task switch + * - Don't do FP software emulation. + * - Proctected mode enabled + */ + movq %cr0, %rax + andq $~(X86_CR0_AM | X86_CR0_WP | X86_CR0_TS | X86_CR0_EM), %rax + orl $(X86_CR0_PG | X86_CR0_PE), %eax + movq %rax, %cr0 + + /* + * Set cr4 to a known state: + * - physical address extension enabled + */ + movq $X86_CR4_PAE, %rax + movq %rax, %cr4 + + movq %rbx, %rdi + call relocate_pages + + popq %rdi + popq %rsi + popq %rbx + popq %rcx + + /* Need to switch to 32-bit mode? */ + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 + jnz call_32_bit + +call_64_bit: + /* Call the image entry point. This should never return. */ + call *%rcx + ud2 + +call_32_bit: + /* Relocate compatibility mode entry point address. */ + movl %edi, %eax + addl $(compatibility_mode - kexec_reloc), %eax + movl %eax, compatibility_mode_far(%rip) + + /* setup idt */ + lidt compat_mode_idt(%rip) + + /* Load compat GDT. */ + movq %rdi, %rax + addq $(compat_mode_gdt - kexec_reloc), %rax + movq %rax, (compat_mode_gdt_desc + 2)(%rip) + lgdt compat_mode_gdt_desc(%rip) + + /* Enter compatibility mode. */ + ljmp *compatibility_mode_far(%rip) + +relocate_pages: + /* %rdi - indirection page maddr */ + cld + movq %rdi, %rcx + xorq %rdi, %rdi + xorq %rsi, %rsi + jmp 1f + +0: /* top, read another word for the indirection page */ + + movq (%rbx), %rcx + addq $8, %rbx +1: + testq $0x1, %rcx /* is it a destination page? */ + jz 2f + movq %rcx, %rdi + andq $0xfffffffffffff000, %rdi + jmp 0b +2: + testq $0x2, %rcx /* is it an indirection page? */ + jz 2f + movq %rcx, %rbx + andq $0xfffffffffffff000, %rbx + jmp 0b +2: + testq $0x4, %rcx /* is it the done indicator? */ + jz 2f + jmp 3f +2: + testq $0x8, %rcx /* is it the source indicator? */ + jz 0b /* Ignore it otherwise */ + movq %rcx, %rsi /* For ever source page do a copy */ + andq $0xfffffffffffff000, %rsi + + movq $512, %rcx + rep movsq + + jmp 0b +3: + ret + + .code32 + +compatibility_mode: + /* Setup some sane segments. */ + movl $0x0008, %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %fs + movl %eax, %gs + movl %eax, %ss + + movl %ecx, %ebp + + /* Disable paging and therefore leave 64 bit mode. */ + movl %cr0, %eax + andl $~X86_CR0_PG, %eax + movl %eax, %cr0 + + /* Disable long mode */ + movl $MSR_EFER, %ecx + rdmsr + andl $~EFER_LME, %eax + wrmsr + + /* Clear cr4 to disable PAE. */ + movl $0, %eax + movl %eax, %cr4 + + /* Call the image entry point. This should never return. */ + call *%ebp + ud2 + + .align 16 +compatibility_mode_far: + .long SYM_PHYS(compatibility_mode) + .word 0x0010 + + .align 16 +compat_mode_gdt_desc: + .word (3*8)-1 + .quad SYM_PHYS(compat_mode_gdt) + + .align 16 +compat_mode_gdt: + .quad 0x0000000000000000 /* null */ + .quad 0x00cf92000000ffff /* 0x0008 ring 0 data */ + .quad 0x00cf9a000000ffff /* 0x0010 ring 0 code, compatibility */ + +compat_mode_idt: + .word 0 /* limit */ + .long 0 /* base */ + + /* + * 16 words of stack are more than enough. + */ + .fill 16,8,0 +reloc_stack: + + .globl kexec_reloc_size + .set kexec_reloc_size, . - kexec_reloc diff --git a/xen/common/kexec.c b/xen/common/kexec.c index f2bda59..a0db760 100644 --- a/xen/common/kexec.c +++ b/xen/common/kexec.c @@ -24,6 +24,7 @@ #include <xen/version.h> #include <xen/console.h> #include <xen/kexec.h> +#include <xen/kimage.h> #include <public/elfnote.h> #include <xsm/xsm.h> #include <xen/cpu.h> @@ -46,7 +47,7 @@ static Elf_Note *xen_crash_note; static cpumask_t crash_saved_cpus; -static xen_kexec_image_t kexec_image[KEXEC_IMAGE_NR]; +static struct kexec_image *kexec_image[KEXEC_IMAGE_NR]; #define KEXEC_FLAG_DEFAULT_POS (KEXEC_IMAGE_NR + 0) #define KEXEC_FLAG_CRASH_POS (KEXEC_IMAGE_NR + 1) @@ -310,14 +311,14 @@ void kexec_crash(void) kexec_common_shutdown(); kexec_crash_save_cpu(); machine_crash_shutdown(); - machine_kexec(&kexec_image[KEXEC_IMAGE_CRASH_BASE + pos]); + machine_kexec(kexec_image[KEXEC_IMAGE_CRASH_BASE + pos]); BUG(); } static long kexec_reboot(void *_image) { - xen_kexec_image_t *image = _image; + struct kexec_image *image = _image; kexecing = TRUE; @@ -733,63 +734,265 @@ static void crash_save_vmcoreinfo(void) #endif } -static int kexec_load_unload_internal(unsigned long op, xen_kexec_load_v1_t *load) +static void kexec_unload_image(struct kexec_image *image) +{ + if ( !image ) + return; + + machine_kexec_unload(image); + kimage_free(image); +} + +static int kexec_exec(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_exec_t exec; + struct kexec_image *image; + int base, bit, pos, ret = -EINVAL; + + if ( unlikely(copy_from_guest(&exec, uarg, 1)) ) + return -EFAULT; + + if ( kexec_load_get_bits(exec.type, &base, &bit) ) + return -EINVAL; + + pos = (test_bit(bit, &kexec_flags) != 0); + + /* Only allow kexec/kdump into loaded images */ + if ( !test_bit(base + pos, &kexec_flags) ) + return -ENOENT; + + switch (exec.type) + { + case KEXEC_TYPE_DEFAULT: + image = kexec_image[base + pos]; + ret = continue_hypercall_on_cpu(0, kexec_reboot, image); + break; + case KEXEC_TYPE_CRASH: + kexec_crash(); /* Does not return */ + break; + } + + return -EINVAL; /* never reached */ +} + +static int kexec_swap_images(int type, struct kexec_image *new, + struct kexec_image **old) { - xen_kexec_image_t *image; int base, bit, pos; - int ret = 0; + int new_slot, old_slot; + + *old = NULL; + + spin_lock(&kexec_lock); + + if ( test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags) ) + { + spin_unlock(&kexec_lock); + return -EBUSY; + } - if ( kexec_load_get_bits(load->type, &base, &bit) ) + if ( kexec_load_get_bits(type, &base, &bit) ) return -EINVAL; pos = (test_bit(bit, &kexec_flags) != 0); + old_slot = base + pos; + new_slot = base + !pos; - /* Load the user data into an unused image */ - if ( op == KEXEC_CMD_kexec_load ) + if ( new ) { - image = &kexec_image[base + !pos]; + kexec_image[new_slot] = new; + set_bit(new_slot, &kexec_flags); + } + change_bit(bit, &kexec_flags); - BUG_ON(test_bit((base + !pos), &kexec_flags)); /* must be free */ + clear_bit(old_slot, &kexec_flags); + *old = kexec_image[old_slot]; - memcpy(image, &load->image, sizeof(*image)); + spin_unlock(&kexec_lock); - if ( !(ret = machine_kexec_load(load->type, base + !pos, image)) ) - { - /* Set image present bit */ - set_bit((base + !pos), &kexec_flags); + return 0; +} - /* Make new image the active one */ - change_bit(bit, &kexec_flags); - } +static int kexec_load_slot(struct kexec_image *kimage) +{ + struct kexec_image *old_kimage; + int ret = -ENOMEM; + + ret = machine_kexec_load(kimage); + if ( ret < 0 ) + goto error; + + crash_save_vmcoreinfo(); + + ret = kexec_swap_images(kimage->type, kimage, &old_kimage); + if ( ret < 0 ) + goto error; + + kexec_unload_image(old_kimage); + + return 0; + +error: + kimage_free(kimage); + return ret; +} + +static uint16_t kexec_load_v1_arch(void) +{ +#ifdef CONFIG_X86 + return is_pv_32on64_domain(dom0) ? EM_386 : EM_X86_64; +#else + return EM_NONE; +#endif +} - crash_save_vmcoreinfo(); +static int kexec_segments_add_segment( + unsigned *nr_segments, xen_kexec_segment_t *segments, + unsigned long mfn) +{ + unsigned long maddr = mfn << PAGE_SHIFT; + int n = *nr_segments; + + /* Need a new segment? */ + if ( n == 0 + || segments[n-1].dest_maddr + segments[n-1].dest_size != maddr ) + { + n++; + if ( n > KEXEC_SEGMENT_MAX ) + return -EINVAL; + *nr_segments = n; + + set_xen_guest_handle(segments[n-1].buf, NULL); + segments[n-1].buf_size = 0; + segments[n-1].dest_maddr = maddr; + segments[n-1].dest_size = 0; } - /* Unload the old image if present and load successful */ - if ( ret == 0 && !test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags) ) + return 0; +} + +static int kexec_segments_from_ind_page(unsigned long mfn, + unsigned *nr_segments, + xen_kexec_segment_t *segments, + bool_t compat) +{ + void *page; + kimage_entry_t *entry; + int ret = 0; + + page = map_domain_page(mfn); + + /* + * Walk the indirection page list, adding destination pages to the + * segments. + */ + for ( entry = page; ; ) { - if ( test_and_clear_bit((base + pos), &kexec_flags) ) + unsigned long ind; + + ind = kimage_entry_ind(entry, compat); + mfn = kimage_entry_mfn(entry, compat); + + switch ( ind ) { - image = &kexec_image[base + pos]; - machine_kexec_unload(load->type, base + pos, image); + case IND_DESTINATION: + ret = kexec_segments_add_segment(nr_segments, segments, mfn); + if ( ret < 0 ) + goto done; + break; + case IND_INDIRECTION: + unmap_domain_page(page); + page = map_domain_page(mfn); + if ( page == NULL ) + return -ENOMEM; + entry = page; + continue; + case IND_DONE: + goto done; + case IND_SOURCE: + segments[*nr_segments-1].dest_size += PAGE_SIZE; + break; + default: + ret = -EINVAL; + goto done; } + entry = kimage_entry_next(entry, compat); } +done: + unmap_domain_page(page); + return ret; +} +static int kexec_do_load_v1(xen_kexec_load_v1_t *load, int compat) +{ + struct kexec_image *kimage = NULL; + xen_kexec_segment_t *segments; + uint16_t arch; + unsigned nr_segments = 0; + unsigned long ind_mfn = load->image.indirection_page >> PAGE_SHIFT; + int ret; + + arch = kexec_load_v1_arch(); + if ( arch == EM_NONE ) + return -ENOSYS; + + segments = xmalloc_array(xen_kexec_segment_t, KEXEC_SEGMENT_MAX); + if ( segments == NULL ) + return -ENOMEM; + + /* + * Work out the image segments (destination only) from the + * indirection pages. + * + * This is needed so we don't allocate pages that will overlap + * with the destination when building the new set of indirection + * pages below. + */ + ret = kexec_segments_from_ind_page(ind_mfn, &nr_segments, segments, compat); + if ( ret < 0 ) + goto error; + + ret = kimage_alloc(&kimage, load->type, arch, load->image.start_address, + nr_segments, segments); + if ( ret < 0 ) + goto error; + + /* + * Build a new set of indirection pages in the native format. + * + * This walks the guest provided indirection pages a second time. + * The guest could have altered then, invalidating the segment + * information constructed above. This will only result in the + * resulting image being potentially unrelocatable. + */ + ret = kimage_build_ind(kimage, ind_mfn, compat); + if ( ret < 0 ) + goto error; + + ret = kexec_load_slot(kimage); + if ( ret < 0 ) + goto error; + + return 0; + +error: + if ( !kimage ) + xfree(segments); + kimage_free(kimage); return ret; } -static int kexec_load_unload(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load_v1(XEN_GUEST_HANDLE_PARAM(void) uarg) { xen_kexec_load_v1_t load; if ( unlikely(copy_from_guest(&load, uarg, 1)) ) return -EFAULT; - return kexec_load_unload_internal(op, &load); + return kexec_do_load_v1(&load, 0); } -static int kexec_load_unload_compat(unsigned long op, - XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) { #ifdef CONFIG_COMPAT compat_kexec_load_v1_t compat_load; @@ -808,49 +1011,113 @@ static int kexec_load_unload_compat(unsigned long op, load.type = compat_load.type; XLAT_kexec_image(&load.image, &compat_load.image); - return kexec_load_unload_internal(op, &load); -#else /* CONFIG_COMPAT */ + return kexec_do_load_v1(&load, 1); +#else return 0; -#endif /* CONFIG_COMPAT */ +#endif } -static int kexec_exec(XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load(XEN_GUEST_HANDLE_PARAM(void) uarg) { - xen_kexec_exec_t exec; - xen_kexec_image_t *image; - int base, bit, pos, ret = -EINVAL; + xen_kexec_load_t load; + xen_kexec_segment_t *segments; + struct kexec_image *kimage = NULL; + int ret; - if ( unlikely(copy_from_guest(&exec, uarg, 1)) ) + if ( copy_from_guest(&load, uarg, 1) ) return -EFAULT; - if ( kexec_load_get_bits(exec.type, &base, &bit) ) + if ( load.nr_segments >= KEXEC_SEGMENT_MAX ) return -EINVAL; - pos = (test_bit(bit, &kexec_flags) != 0); - - /* Only allow kexec/kdump into loaded images */ - if ( !test_bit(base + pos, &kexec_flags) ) - return -ENOENT; + segments = xmalloc_array(xen_kexec_segment_t, load.nr_segments); + if ( segments == NULL ) + return -ENOMEM; - switch (exec.type) + if ( copy_from_guest(segments, load.segments, load.nr_segments) ) { - case KEXEC_TYPE_DEFAULT: - image = &kexec_image[base + pos]; - ret = continue_hypercall_on_cpu(0, kexec_reboot, image); - break; - case KEXEC_TYPE_CRASH: - kexec_crash(); /* Does not return */ - break; + ret = -EFAULT; + goto error; } - return -EINVAL; /* never reached */ + ret = kimage_alloc(&kimage, load.type, load.arch, load.entry_maddr, + load.nr_segments, segments); + if ( ret < 0 ) + goto error; + + ret = kimage_load_segments(kimage); + if ( ret < 0 ) + goto error; + + ret = kexec_load_slot(kimage); + if ( ret < 0 ) + goto error; + + return 0; + +error: + if ( ! kimage ) + xfree(segments); + kimage_free(kimage); + return ret; +} + +static int kexec_do_unload(xen_kexec_unload_t *unload) +{ + struct kexec_image *old_kimage; + int ret; + + ret = kexec_swap_images(unload->type, NULL, &old_kimage); + if ( ret < 0 ) + return ret; + + kexec_unload_image(old_kimage); + + return 0; +} + +static int kexec_unload_v1(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_load_v1_t load; + xen_kexec_unload_t unload; + + if ( copy_from_guest(&load, uarg, 1) ) + return -EFAULT; + + unload.type = load.type; + return kexec_do_unload(&unload); +} + +static int kexec_unload_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ +#ifdef CONFIG_COMPAT + compat_kexec_load_v1_t compat_load; + xen_kexec_unload_t unload; + + if ( copy_from_guest(&compat_load, uarg, 1) ) + return -EFAULT; + + unload.type = compat_load.type; + return kexec_do_unload(&unload); +#else + return 0; +#endif +} + +static int kexec_unload(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_unload_t unload; + + if ( unlikely(copy_from_guest(&unload, uarg, 1)) ) + return -EFAULT; + + return kexec_do_unload(&unload); } static int do_kexec_op_internal(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg, bool_t compat) { - unsigned long flags; int ret = -EINVAL; ret = xsm_kexec(XSM_PRIV); @@ -866,20 +1133,26 @@ static int do_kexec_op_internal(unsigned long op, ret = kexec_get_range(uarg); break; case KEXEC_CMD_kexec_load_v1: + if ( compat ) + ret = kexec_load_v1_compat(uarg); + else + ret = kexec_load_v1(uarg); + break; case KEXEC_CMD_kexec_unload_v1: - spin_lock_irqsave(&kexec_lock, flags); - if (!test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags)) - { - if (compat) - ret = kexec_load_unload_compat(op, uarg); - else - ret = kexec_load_unload(op, uarg); - } - spin_unlock_irqrestore(&kexec_lock, flags); + if ( compat ) + ret = kexec_unload_v1_compat(uarg); + else + ret = kexec_unload_v1(uarg); break; case KEXEC_CMD_kexec: ret = kexec_exec(uarg); break; + case KEXEC_CMD_kexec_load: + ret = kexec_load(uarg); + break; + case KEXEC_CMD_kexec_unload: + ret = kexec_unload(uarg); + break; } return ret; diff --git a/xen/common/kimage.c b/xen/common/kimage.c index 6f5185c..3d6a679 100644 --- a/xen/common/kimage.c +++ b/xen/common/kimage.c @@ -831,6 +831,84 @@ int kimage_load_segments(struct kexec_image *image) return 0; } +kimage_entry_t *kimage_entry_next(kimage_entry_t *entry, bool_t compat) +{ + if ( compat ) + return (kimage_entry_t *)((uint32_t *)entry + 1); + return entry + 1; +} + +unsigned long kimage_entry_mfn(kimage_entry_t *entry, bool_t compat) +{ + if ( compat ) + return *(uint32_t *)entry >> PAGE_SHIFT; + return *entry >> PAGE_SHIFT; +} + +unsigned long kimage_entry_ind(kimage_entry_t *entry, bool_t compat) +{ + if ( compat ) + return *(uint32_t *)entry & 0xf; + return *entry & 0xf; +} + +int kimage_build_ind(struct kexec_image *image, unsigned long ind_mfn, + bool_t compat) +{ + void *page; + kimage_entry_t *entry; + int ret = 0; + + page = map_domain_page(ind_mfn); + if ( page == NULL ) + return -ENOMEM; + + /* + * Walk the guest-supplied indirection pages, adding entries to + * the image's indirection pages. + */ + for ( entry = page; ; ) + { + unsigned long ind; + unsigned long mfn; + + ind = kimage_entry_ind(entry, compat); + mfn = kimage_entry_mfn(entry, compat); + + switch ( ind ) + { + case IND_DESTINATION: + ret = kimage_set_destination(image, mfn << PAGE_SHIFT); + if ( ret < 0 ) + goto done; + break; + case IND_INDIRECTION: + unmap_domain_page(page); + page = map_domain_page(mfn); + entry = page; + continue; + case IND_DONE: + kimage_terminate(image); + goto done; + case IND_SOURCE: + ret = kimage_add_page(image, mfn << PAGE_SHIFT); + if ( ret < 0 ) + goto done; + break; + default: + ret = -EINVAL; + goto done; + } + entry = kimage_entry_next(entry, compat); + } +done: + unmap_domain_page(page); + return ret; +} + + + + /* * Local variables: * mode: C diff --git a/xen/include/asm-x86/fixmap.h b/xen/include/asm-x86/fixmap.h index 2eefcf4..1695228 100644 --- a/xen/include/asm-x86/fixmap.h +++ b/xen/include/asm-x86/fixmap.h @@ -57,9 +57,6 @@ enum fixed_addresses { FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1, FIX_HPET_BASE, FIX_CYCLONE_TIMER, - FIX_KEXEC_BASE_0, - FIX_KEXEC_BASE_END = FIX_KEXEC_BASE_0 \ - + ((KEXEC_XEN_NO_PAGES >> 1) * KEXEC_IMAGE_NR) - 1, FIX_IOMMU_REGS_BASE_0, FIX_IOMMU_REGS_END = FIX_IOMMU_REGS_BASE_0 + MAX_IOMMUS-1, FIX_IOMMU_MMIO_BASE_0, diff --git a/xen/include/asm-x86/machine_kexec.h b/xen/include/asm-x86/machine_kexec.h new file mode 100644 index 0000000..ec41099 --- /dev/null +++ b/xen/include/asm-x86/machine_kexec.h @@ -0,0 +1,14 @@ +#ifndef __X86_MACHINE_KEXEC_H__ +#define __X86_MACHINE_KEXEC_H__ + +#define KEXEC_RELOC_FLAG_COMPAT 0x1 /* 32-bit image */ + +#ifndef __ASSEMBLY__ + +extern void kexec_reloc(unsigned long reloc_code, unsigned long reloc_pt, + unsigned long ind_maddr, unsigned long entry_maddr, + unsigned long flags); + +#endif + +#endif /* __X86_MACHINE_KEXEC_H__ */ diff --git a/xen/include/xen/kexec.h b/xen/include/xen/kexec.h index 1a5dda1..7bb9213 100644 --- a/xen/include/xen/kexec.h +++ b/xen/include/xen/kexec.h @@ -6,6 +6,7 @@ #include <public/kexec.h> #include <asm/percpu.h> #include <xen/elfcore.h> +#include <xen/kimage.h> typedef struct xen_kexec_reserve { unsigned long size; @@ -40,11 +41,11 @@ extern enum low_crashinfo low_crashinfo_mode; extern paddr_t crashinfo_maxaddr_bits; void kexec_early_calculations(void); -int machine_kexec_load(int type, int slot, xen_kexec_image_t *image); -void machine_kexec_unload(int type, int slot, xen_kexec_image_t *image); +int machine_kexec_load(struct kexec_image *image); +void machine_kexec_unload(struct kexec_image *image); void machine_kexec_reserved(xen_kexec_reserve_t *reservation); -void machine_reboot_kexec(xen_kexec_image_t *image); -void machine_kexec(xen_kexec_image_t *image); +void machine_reboot_kexec(struct kexec_image *image); +void machine_kexec(struct kexec_image *image); void kexec_crash(void); void kexec_crash_save_cpu(void); crash_xen_info_t *kexec_crash_save_info(void); @@ -52,11 +53,6 @@ void machine_crash_shutdown(void); int machine_kexec_get(xen_kexec_range_t *range); int machine_kexec_get_xen(xen_kexec_range_t *range); -void compat_machine_kexec(unsigned long rnk, - unsigned long indirection_page, - unsigned long *page_list, - unsigned long start_address); - /* vmcoreinfo stuff */ #define VMCOREINFO_BYTES (4096) #define VMCOREINFO_NOTE_NAME "VMCOREINFO_XEN" diff --git a/xen/include/xen/kimage.h b/xen/include/xen/kimage.h index 9a785a1..7628e0a 100644 --- a/xen/include/xen/kimage.h +++ b/xen/include/xen/kimage.h @@ -50,6 +50,12 @@ int kimage_load_segments(struct kexec_image *image); struct page_info *kimage_alloc_control_page(struct kexec_image *image, unsigned memflags); +kimage_entry_t *kimage_entry_next(kimage_entry_t *entry, bool_t compat); +unsigned long kimage_entry_mfn(kimage_entry_t *entry, bool_t compat); +unsigned long kimage_entry_ind(kimage_entry_t *entry, bool_t compat); +int kimage_build_ind(struct kexec_image *image, unsigned long ind_mfn, + bool_t compat); + #endif /* __XEN_KIMAGE_H__ */ /* -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-08 18:59 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel @ 2013-04-09 21:02 ` Daniel Kiper 2013-04-15 18:58 ` David Vrabel 2013-04-16 14:57 ` David Vrabel 0 siblings, 2 replies; 34+ messages in thread From: Daniel Kiper @ 2013-04-09 21:02 UTC (permalink / raw) To: David Vrabel; +Cc: Ian Jackson, kexec, Ian Campbell, xen-devel On Mon, Apr 08, 2013 at 07:59:50PM +0100, David Vrabel wrote: > From: David Vrabel <david.vrabel@citrix.com> > > In the existing kexec hypercall, the load and unload ops depend on > internals of the Linux kernel (the page list and code page provided by > the kernel). The code page is used to transition between Xen context > and the image so using kernel code doesn't make sense and will not > work for PVH guests. > > Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops > that no longer require a code page to be provided by the guest -- Xen > now provides the code for calling the image directly. > > The new load op looks similar to the Linux kexec_load system call and > allows the guest to provide the image data to be loaded. The guest > specifies the architecture of the image which may be a 32-bit subarch > of the hypervisor's architecture (i.e., an EM_386 image on an > EM_X86_64 hypervisor). > > The toolstack can now load images without kernel involvement. This is > required for supporting kexec when using a dom0 with an upstream > kernel. > > Crash images are copied directly into the crash region on load. > Default images are copied into domheap pages and a list of source and > destination machine addresses is created. This is list is used in > kexec_reloc() to relocate the image to its destination. > > The old load and unload sub-ops are still available (as > KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top > of the new infrastructure. > > Signed-off-by: David Vrabel <david.vrabel@citrix.com> [...] > diff --git a/xen/arch/x86/x86_64/kexec_reloc.S b/xen/arch/x86/x86_64/kexec_reloc.S > new file mode 100644 > index 0000000..9d09c35 > --- /dev/null > +++ b/xen/arch/x86/x86_64/kexec_reloc.S > @@ -0,0 +1,215 @@ > +/* > + * Relocate a kexec_image to its destination and call it. > + * > + * Copyright (C) 2013 Citrix Systems R&D Ltd. > + * > + * Portions derived from Linux's arch/x86/kernel/relocate_kernel_64.S. > + * > + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> > + * > + * This source code is licensed under the GNU General Public License, > + * Version 2. See the file COPYING for more details. > + */ > +#include <xen/config.h> > + > +#include <asm/asm_defns.h> > +#include <asm/msr.h> > +#include <asm/page.h> > +#include <asm/machine_kexec.h> > + > +/* The unrelocated physical address of a symbol. */ > +#define SYM_PHYS(sym) ((sym) - __XEN_VIRT_START) > + > +/* Load physical address of symbol into register and relocate it. */ > +#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ > + add xen_phys_start(%rip), reg > + > + .text > + .align PAGE_SIZE > + .code64 > + > +ENTRY(kexec_reloc) > + /* %rdi - code_page maddr */ > + /* %rsi - page table maddr */ > + /* %rdx - indirection page maddr */ > + /* %rcx - entry maddr */ > + /* %r8 - flags */ > + > + mov %rdx, %rbx movq? > + > + /* Setup stack. */ > + RELOCATE_SYM(reloc_stack, %rax) > + mov %rax, %rsp Ditto? > + > + /* Load reloc page table. */ > + movq %rsi, %cr3 ...because at least you use movq here... ...etc... > + > + /* Jump to identity mapped code. */ > + movq %rdi, %r9 > + addq $(identity_mapped - kexec_reloc), %r9 > + > + jmp *%r9 jmpq *(identity_mapped - kexec_reloc)(%rdi) > + > +identity_mapped: > + pushq %rcx > + pushq %rbx > + pushq %rsi > + pushq %rdi > + > + /* > + * Set cr0 to a known state: > + * - Paging enabled > + * - Alignment check disabled > + * - Write protect disabled > + * - No task switch > + * - Don't do FP software emulation. > + * - Proctected mode enabled > + */ > + movq %cr0, %rax > + andq $~(X86_CR0_AM | X86_CR0_WP | X86_CR0_TS | X86_CR0_EM), %rax > + orl $(X86_CR0_PG | X86_CR0_PE), %eax > + movq %rax, %cr0 > + > + /* > + * Set cr4 to a known state: > + * - physical address extension enabled > + */ > + movq $X86_CR4_PAE, %rax > + movq %rax, %cr4 > + > + movq %rbx, %rdi > + call relocate_pages > + > + popq %rdi > + popq %rsi > + popq %rbx > + popq %rcx > + > + /* Need to switch to 32-bit mode? */ > + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 > + jnz call_32_bit > + > +call_64_bit: > + /* Call the image entry point. This should never return. */ > + call *%rcx > + ud2 > + > +call_32_bit: > + /* Relocate compatibility mode entry point address. */ > + movl %edi, %eax > + addl $(compatibility_mode - kexec_reloc), %eax leal (compatibility_mode - kexec_reloc)(%edi), %eax > + movl %eax, compatibility_mode_far(%rip) > + > + /* setup idt */ > + lidt compat_mode_idt(%rip) > + > + /* Load compat GDT. */ > + movq %rdi, %rax > + addq $(compat_mode_gdt - kexec_reloc), %rax leaq (compat_mode_gdt - kexec_reloc)(%rdi), %rax [...] > diff --git a/xen/common/kexec.c b/xen/common/kexec.c [...] > -static int kexec_load_unload_compat(unsigned long op, > - XEN_GUEST_HANDLE_PARAM(void) uarg) > +static int kexec_load_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) > { > #ifdef CONFIG_COMPAT > compat_kexec_load_v1_t compat_load; > @@ -808,49 +1011,113 @@ static int kexec_load_unload_compat(unsigned long op, > load.type = compat_load.type; > XLAT_kexec_image(&load.image, &compat_load.image); > > - return kexec_load_unload_internal(op, &load); > -#else /* CONFIG_COMPAT */ > + return kexec_do_load_v1(&load, 1); > +#else Why did you removed comment? > return 0; Why not -ENOSYS? > -#endif /* CONFIG_COMPAT */ > +#endif Why did you removed comment? [...] > +static int kexec_unload_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) > +{ > +#ifdef CONFIG_COMPAT > + compat_kexec_load_v1_t compat_load; > + xen_kexec_unload_t unload; > + > + if ( copy_from_guest(&compat_load, uarg, 1) ) > + return -EFAULT; > + > + unload.type = compat_load.type; > + return kexec_do_unload(&unload); > +#else > + return 0; Why not -ENOSYS? > +#endif > +} Please check other similar places too. Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-09 21:02 ` Daniel Kiper @ 2013-04-15 18:58 ` David Vrabel 2013-04-16 12:05 ` Daniel Kiper 2013-04-16 14:57 ` David Vrabel 1 sibling, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-15 18:58 UTC (permalink / raw) To: Daniel Kiper Cc: Ian Jackson, kexec@lists.infradead.org, Ian Campbell, xen-devel@lists.xen.org On 09/04/13 22:02, Daniel Kiper wrote: > On Mon, Apr 08, 2013 at 07:59:50PM +0100, David Vrabel wrote: >> >> + >> + /* Jump to identity mapped code. */ >> + movq %rdi, %r9 >> + addq $(identity_mapped - kexec_reloc), %r9 >> + >> + jmp *%r9 > > jmpq *(identity_mapped - kexec_reloc)(%rdi) This isn't equivalent. It loads the value at the specified memory location and jumps to that address. leaq (identity_mapped - kexec_reloc)(%rdi), %rax jmpq *%rax Does the right thing. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-15 18:58 ` David Vrabel @ 2013-04-16 12:05 ` Daniel Kiper 0 siblings, 0 replies; 34+ messages in thread From: Daniel Kiper @ 2013-04-16 12:05 UTC (permalink / raw) To: David Vrabel Cc: Ian Jackson, kexec@lists.infradead.org, Ian Campbell, xen-devel@lists.xen.org On Mon, Apr 15, 2013 at 07:58:30PM +0100, David Vrabel wrote: > On 09/04/13 22:02, Daniel Kiper wrote: > > On Mon, Apr 08, 2013 at 07:59:50PM +0100, David Vrabel wrote: > >> > >> + > >> + /* Jump to identity mapped code. */ > >> + movq %rdi, %r9 > >> + addq $(identity_mapped - kexec_reloc), %r9 > >> + > >> + jmp *%r9 > > > > jmpq *(identity_mapped - kexec_reloc)(%rdi) > > This isn't equivalent. It loads the value at the specified memory > location and jumps to that address. > > leaq (identity_mapped - kexec_reloc)(%rdi), %rax > jmpq *%rax > > Does the right thing. You are right. Sorry for confusion. Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-09 21:02 ` Daniel Kiper 2013-04-15 18:58 ` David Vrabel @ 2013-04-16 14:57 ` David Vrabel 1 sibling, 0 replies; 34+ messages in thread From: David Vrabel @ 2013-04-16 14:57 UTC (permalink / raw) To: Daniel Kiper Cc: Ian Jackson, kexec@lists.infradead.org, Ian Campbell, xen-devel@lists.xen.org On 09/04/13 22:02, Daniel Kiper wrote: > On Mon, Apr 08, 2013 at 07:59:50PM +0100, David Vrabel wrote: >> >> -static int kexec_load_unload_compat(unsigned long op, >> - XEN_GUEST_HANDLE_PARAM(void) uarg) >> +static int kexec_load_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) >> { >> #ifdef CONFIG_COMPAT >> compat_kexec_load_v1_t compat_load; >> @@ -808,49 +1011,113 @@ static int kexec_load_unload_compat(unsigned long op, >> load.type = compat_load.type; >> XLAT_kexec_image(&load.image, &compat_load.image); >> >> - return kexec_load_unload_internal(op, &load); >> -#else /* CONFIG_COMPAT */ >> + return kexec_do_load_v1(&load, 1); >> +#else > > Why did you removed comment? It's unhelpful clutter when the #if/#else/#endif are close together. >> return 0; > > Why not -ENOSYS? It's unreachable code so it doesn't matter. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* [PATCH 6/8] xen: kexec crash image when dom0 crashes 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel ` (4 preceding siblings ...) 2013-04-08 18:59 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel @ 2013-04-08 18:59 ` David Vrabel 2013-04-09 21:11 ` Daniel Kiper 2013-04-08 18:59 ` [PATCH 7/8] libxc: add hypercall buffer arrays David Vrabel 2013-04-08 18:59 ` [PATCH 8/8] libxc: add API for kexec hypercall David Vrabel 7 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw) To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell From: David Vrabel <david.vrabel@citrix.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- xen/common/shutdown.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/xen/common/shutdown.c b/xen/common/shutdown.c index 73a7d7b..b676a03 100644 --- a/xen/common/shutdown.c +++ b/xen/common/shutdown.c @@ -47,6 +47,9 @@ void dom0_shutdown(u8 reason) { debugger_trap_immediate(); printk("Domain 0 crashed: "); +#ifdef CONFIG_KEXEC + kexec_crash(); +#endif maybe_reboot(); break; /* not reached */ } -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* Re: [PATCH 6/8] xen: kexec crash image when dom0 crashes 2013-04-08 18:59 ` [PATCH 6/8] xen: kexec crash image when dom0 crashes David Vrabel @ 2013-04-09 21:11 ` Daniel Kiper 0 siblings, 0 replies; 34+ messages in thread From: Daniel Kiper @ 2013-04-09 21:11 UTC (permalink / raw) To: David Vrabel; +Cc: Ian Jackson, kexec, Ian Campbell, xen-devel On Mon, Apr 08, 2013 at 07:59:51PM +0100, David Vrabel wrote: > From: David Vrabel <david.vrabel@citrix.com> > > Signed-off-by: David Vrabel <david.vrabel@citrix.com> > --- > xen/common/shutdown.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/xen/common/shutdown.c b/xen/common/shutdown.c > index 73a7d7b..b676a03 100644 > --- a/xen/common/shutdown.c > +++ b/xen/common/shutdown.c > @@ -47,6 +47,9 @@ void dom0_shutdown(u8 reason) > { > debugger_trap_immediate(); > printk("Domain 0 crashed: "); Maybe printk("Domain 0 crashed...\n") because kexec_crash() does not print any message and current version looks a bit strange i.e. it suggest that something should be printed but something has failed... If yes then messages which could be printed immediately after "Domain 0 crashed...\n" should start from "..." e.g. "...rebooting...". > +#ifdef CONFIG_KEXEC > + kexec_crash(); > +#endif > maybe_reboot(); > break; /* not reached */ > } Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* [PATCH 7/8] libxc: add hypercall buffer arrays 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel ` (5 preceding siblings ...) 2013-04-08 18:59 ` [PATCH 6/8] xen: kexec crash image when dom0 crashes David Vrabel @ 2013-04-08 18:59 ` David Vrabel 2013-04-08 18:59 ` [PATCH 8/8] libxc: add API for kexec hypercall David Vrabel 7 siblings, 0 replies; 34+ messages in thread From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw) To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell From: David Vrabel <david.vrabel@citrix.com> Hypercall buffer arrays are used when a hypercall takes a variable length array of buffers. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> --- tools/libxc/xc_hcall_buf.c | 73 ++++++++++++++++++++++++++++++++++++++++++++ tools/libxc/xenctrl.h | 27 ++++++++++++++++ 2 files changed, 100 insertions(+), 0 deletions(-) diff --git a/tools/libxc/xc_hcall_buf.c b/tools/libxc/xc_hcall_buf.c index c354677..e762a93 100644 --- a/tools/libxc/xc_hcall_buf.c +++ b/tools/libxc/xc_hcall_buf.c @@ -228,6 +228,79 @@ void xc__hypercall_bounce_post(xc_interface *xch, xc_hypercall_buffer_t *b) xc__hypercall_buffer_free(xch, b); } +struct xc_hypercall_buffer_array { + unsigned max_bufs; + xc_hypercall_buffer_t *bufs; +}; + +xc_hypercall_buffer_array_t *xc_hypercall_buffer_array_create(xc_interface *xch, + unsigned n) +{ + xc_hypercall_buffer_array_t *array; + xc_hypercall_buffer_t *bufs = NULL; + + array = malloc(sizeof(*array)); + if ( array == NULL ) + goto error; + + bufs = calloc(n, sizeof(*bufs)); + if ( bufs == NULL ) + goto error; + + array->max_bufs = n; + array->bufs = bufs; + + return array; + +error: + free(bufs); + free(array); + return NULL; +} + +void *xc__hypercall_buffer_array_alloc(xc_interface *xch, + xc_hypercall_buffer_array_t *array, + unsigned index, + xc_hypercall_buffer_t *hbuf, + size_t size) +{ + void *buf; + + if ( index >= array->max_bufs || array->bufs[index].hbuf ) + abort(); + + buf = xc__hypercall_buffer_alloc(xch, hbuf, size); + if ( buf ) + array->bufs[index] = *hbuf; + return buf; +} + +void *xc__hypercall_buffer_array_get(xc_interface *xch, + xc_hypercall_buffer_array_t *array, + unsigned index, + xc_hypercall_buffer_t *hbuf) +{ + if ( index >= array->max_bufs || array->bufs[index].hbuf == NULL ) + abort(); + + *hbuf = array->bufs[index]; + return array->bufs[index].hbuf; +} + +void xc_hypercall_buffer_array_destroy(xc_interface *xc, + xc_hypercall_buffer_array_t *array) +{ + unsigned i; + + if ( array == NULL ) + return; + + for (i = 0; i < array->max_bufs; i++ ) + xc__hypercall_buffer_free(xc, &array->bufs[i]); + free(array->bufs); + free(array); +} + /* * Local variables: * mode: C diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h index 32122fd..c3b2c28 100644 --- a/tools/libxc/xenctrl.h +++ b/tools/libxc/xenctrl.h @@ -317,6 +317,33 @@ void xc__hypercall_buffer_free_pages(xc_interface *xch, xc_hypercall_buffer_t *b #define xc_hypercall_buffer_free_pages(_xch, _name, _nr) xc__hypercall_buffer_free_pages(_xch, HYPERCALL_BUFFER(_name), _nr) /* + * Array of hypercall buffers. + * + * Create an array with xc_hypercall_buffer_array_create() and + * populate it by declaring one hypercall buffer in a loop and + * allocating the buffer with xc_hypercall_buffer_array_alloc(). + * + * To access a previously allocated buffers, declare a new hypercall + * buffer and call xc_hypercall_buffer_array_get(). + * + * Destroy the array with xc_hypercall_buffer_array_destroy() to free + * the array and all its alocated hypercall buffers. + */ +struct xc_hypercall_buffer_array; +typedef struct xc_hypercall_buffer_array xc_hypercall_buffer_array_t; + +xc_hypercall_buffer_array_t *xc_hypercall_buffer_array_create(xc_interface *xch, unsigned n); +void *xc__hypercall_buffer_array_alloc(xc_interface *xch, xc_hypercall_buffer_array_t *array, + unsigned index, xc_hypercall_buffer_t *hbuf, size_t size); +#define xc_hypercall_buffer_array_alloc(_xch, _array, _index, _name, _size) \ + xc__hypercall_buffer_array_alloc(_xch, _array, _index, HYPERCALL_BUFFER(_name), _size) +void *xc__hypercall_buffer_array_get(xc_interface *xch, xc_hypercall_buffer_array_t *array, + unsigned index, xc_hypercall_buffer_t *hbuf); +#define xc_hypercall_buffer_array_get(_xch, _array, _index, _name, _size) \ + xc__hypercall_buffer_array_get(_xch, _array, _index, HYPERCALL_BUFFER(_name)) +void xc_hypercall_buffer_array_destroy(xc_interface *xc, xc_hypercall_buffer_array_t *array); + +/* * CPUMAP handling */ typedef uint8_t *xc_cpumap_t; -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* [PATCH 8/8] libxc: add API for kexec hypercall 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel ` (6 preceding siblings ...) 2013-04-08 18:59 ` [PATCH 7/8] libxc: add hypercall buffer arrays David Vrabel @ 2013-04-08 18:59 ` David Vrabel 7 siblings, 0 replies; 34+ messages in thread From: David Vrabel @ 2013-04-08 18:59 UTC (permalink / raw) To: xen-devel; +Cc: Ian Jackson, Daniel Kiper, kexec, David Vrabel, Ian Campbell From: David Vrabel <david.vrabel@citrix.com> Add xc_kexec_exec(), xc_kexec_get_ranges(), xc_kexec_load(), and xc_kexec_unload(). The load and unload calls require the v2 load and unload ops. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Acked-by: Ian Campbell <ian.campbell@citrix.com> --- tools/libxc/Makefile | 1 + tools/libxc/xc_kexec.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++++ tools/libxc/xenctrl.h | 55 +++++++++++++++++++ 3 files changed, 196 insertions(+), 0 deletions(-) create mode 100644 tools/libxc/xc_kexec.c diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile index d44abf9..39badf9 100644 --- a/tools/libxc/Makefile +++ b/tools/libxc/Makefile @@ -31,6 +31,7 @@ CTRL_SRCS-y += xc_mem_access.c CTRL_SRCS-y += xc_memshr.c CTRL_SRCS-y += xc_hcall_buf.c CTRL_SRCS-y += xc_foreign_memory.c +CTRL_SRCS-y += xc_kexec.c CTRL_SRCS-y += xtl_core.c CTRL_SRCS-y += xtl_logger_stdio.c CTRL_SRCS-$(CONFIG_X86) += xc_pagetab.c diff --git a/tools/libxc/xc_kexec.c b/tools/libxc/xc_kexec.c new file mode 100644 index 0000000..bd83dd3 --- /dev/null +++ b/tools/libxc/xc_kexec.c @@ -0,0 +1,140 @@ +/****************************************************************************** + * xc_kexec.c + * + * API for loading and executing kexec images. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; + * version 2.1 of the License. + * + * Copyright (C) 2013 Citrix Systems R&D Ltd. + */ +#include "xc_private.h" + +int xc_kexec_exec(xc_interface *xch, int type) +{ + DECLARE_HYPERCALL; + DECLARE_HYPERCALL_BUFFER(xen_kexec_exec_t, exec); + int ret = -1; + + exec = xc_hypercall_buffer_alloc(xch, exec, sizeof(*exec)); + if ( exec == NULL ) + { + PERROR("Count not alloc bounce buffer for kexec_exec hypercall"); + goto out; + } + + exec->type = type; + + hypercall.op = __HYPERVISOR_kexec_op; + hypercall.arg[0] = KEXEC_CMD_kexec; + hypercall.arg[1] = HYPERCALL_BUFFER_AS_ARG(exec); + + ret = do_xen_hypercall(xch, &hypercall); + +out: + xc_hypercall_buffer_free(xch, exec); + + return ret; +} + +int xc_kexec_get_range(xc_interface *xch, int range, int nr, + uint64_t *size, uint64_t *start) +{ + DECLARE_HYPERCALL; + DECLARE_HYPERCALL_BUFFER(xen_kexec_range_t, get_range); + int ret = -1; + + get_range = xc_hypercall_buffer_alloc(xch, get_range, sizeof(*get_range)); + if ( get_range == NULL ) + { + PERROR("Could not alloc bounce buffer for kexec_get_range hypercall"); + goto out; + } + + get_range->range = range; + get_range->nr = nr; + + hypercall.op = __HYPERVISOR_kexec_op; + hypercall.arg[0] = KEXEC_CMD_kexec_get_range; + hypercall.arg[1] = HYPERCALL_BUFFER_AS_ARG(get_range); + + ret = do_xen_hypercall(xch, &hypercall); + + *size = get_range->size; + *start = get_range->start; + +out: + xc_hypercall_buffer_free(xch, get_range); + + return ret; +} + +int xc_kexec_load(xc_interface *xch, uint8_t type, uint16_t arch, + uint64_t entry_maddr, + uint32_t nr_segments, xen_kexec_segment_t *segments) +{ + int ret = -1; + DECLARE_HYPERCALL; + DECLARE_HYPERCALL_BOUNCE(segments, sizeof(*segments) * nr_segments, + XC_HYPERCALL_BUFFER_BOUNCE_IN); + DECLARE_HYPERCALL_BUFFER(xen_kexec_load_t, load); + + if ( xc_hypercall_bounce_pre(xch, segments) ) + { + PERROR("Could not allocate bounce buffer for kexec load hypercall"); + goto out; + } + load = xc_hypercall_buffer_alloc(xch, load, sizeof(*load)); + if ( load == NULL ) + { + PERROR("Could not allocate buffer for kexec load hypercall"); + goto out; + } + + load->type = type; + load->arch = arch; + load->entry_maddr = entry_maddr; + load->nr_segments = nr_segments; + set_xen_guest_handle(load->segments, segments); + + hypercall.op = __HYPERVISOR_kexec_op; + hypercall.arg[0] = KEXEC_CMD_kexec_load; + hypercall.arg[1] = HYPERCALL_BUFFER_AS_ARG(load); + + ret = do_xen_hypercall(xch, &hypercall); + +out: + xc_hypercall_buffer_free(xch, load); + xc_hypercall_bounce_post(xch, segments); + + return ret; +} + +int xc_kexec_unload(xc_interface *xch, int type) +{ + DECLARE_HYPERCALL; + DECLARE_HYPERCALL_BUFFER(xen_kexec_unload_t, unload); + int ret = -1; + + unload = xc_hypercall_buffer_alloc(xch, unload, sizeof(*unload)); + if ( unload == NULL ) + { + PERROR("Count not alloc buffer for kexec unload hypercall"); + goto out; + } + + unload->type = type; + + hypercall.op = __HYPERVISOR_kexec_op; + hypercall.arg[0] = KEXEC_CMD_kexec_unload; + hypercall.arg[1] = HYPERCALL_BUFFER_AS_ARG(unload); + + ret = do_xen_hypercall(xch, &hypercall); + +out: + xc_hypercall_buffer_free(xch, unload); + + return ret; +} diff --git a/tools/libxc/xenctrl.h b/tools/libxc/xenctrl.h index c3b2c28..b6bab4e 100644 --- a/tools/libxc/xenctrl.h +++ b/tools/libxc/xenctrl.h @@ -46,6 +46,7 @@ #include <xen/hvm/params.h> #include <xen/xsm/flask_op.h> #include <xen/tmem.h> +#include <xen/kexec.h> #include "xentoollog.h" @@ -2263,4 +2264,58 @@ int xc_compression_uncompress_page(xc_interface *xch, char *compbuf, unsigned long compbuf_size, unsigned long *compbuf_pos, char *dest); +/* + * Execute an image previously loaded with xc_kexec_load(). + * + * Does not return on success. + * + * Fails with: + * ENOENT if the specified image has not been loaded. + */ +int xc_kexec_exec(xc_interface *xch, int type); + +/* + * Find the machine address and size of certain memory areas. + * + * KEXEC_RANGE_MA_CRASH crash area + * KEXEC_RANGE_MA_XEN Xen itself + * KEXEC_RANGE_MA_CPU CPU note for CPU number 'nr' + * KEXEC_RANGE_MA_XENHEAP xenheap + * KEXEC_RANGE_MA_EFI_MEMMAP EFI Memory Map + * KEXEC_RANGE_MA_VMCOREINFO vmcoreinfo + * + * Fails with: + * EINVAL if the range or CPU number isn't valid. + */ +int xc_kexec_get_range(xc_interface *xch, int range, int nr, + uint64_t *size, uint64_t *start); + +/* + * Load a kexec image into memory. + * + * The image may be of type KEXEC_TYPE_DEFAULT (executed on request) + * or KEXEC_TYPE_CRASH (executed on a crash). + * + * The image architecture may be a 32-bit variant of the hypervisor + * architecture (e.g, EM_386 on a x86-64 hypervisor). + * + * Fails with: + * ENOMEM if there is insufficient memory for the new image. + * EINVAL if the image does not fit into the crash area or the entry + * point isn't within one of segments. + * EBUSY if another image is being executed. + */ +int xc_kexec_load(xc_interface *xch, uint8_t type, uint16_t arch, + uint64_t entry_maddr, + uint32_t nr_segments, xen_kexec_segment_t *segments); + +/* + * Unload a kexec image. + * + * This prevents a KEXEC_TYPE_DEFAULT or KEXEC_TYPE_CRASH image from + * being executed. The crash images are not cleared from the crash + * region. + */ +int xc_kexec_unload(xc_interface *xch, int type); + #endif /* XENCTRL_H */ -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* [PATCHv4 0/8] kexec: extend kexec hypercall for use with pv-ops kernels @ 2013-04-16 17:13 David Vrabel 2013-04-16 17:13 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel 0 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-16 17:13 UTC (permalink / raw) To: xen-devel; +Cc: kexec, Daniel Kiper, Keir Fraser, David Vrabel The series improves the kexec hypercall by making Xen responsible for loading and relocating the image. This allows kexec to be usable by pv-ops kernels and should allow kexec to be usable from a HVM or PVH privileged domain. This has now missed the code freeze deadline but could it be considered for 4.3 anyway? kexec isn't a core piece of functionality and I see minimal risk of introducing regressions to Xen as a whole with this series. The first patch is a simple clean-up. The second patch allows hypercall structures to be ABI compatible between 32- and 64-bit guests (by reusing stuff present for domctls and sysctls). This seems better than having to keep adding compat handling for new hypercalls etc. Patch 3 introduces the new ABI. Patch 4 and 5 nearly completely reimplement the kexec load, unload and exec sub-ops. The old load_v1 sub-op is then implemented on top of the new code. Patch 6 calls the kexec image when dom0 crashes. This avoids having to alter dom0 kernels to do a exec sub-op call on crash -- a SHUTDOWN_crash by dom0 will trigger the kexec. Patches 7 and 8 add the libxc API for the kexec calls. These have been acked-by Ian Campbell already. The required patch series for kexec-tools have previously been posted and this series has been rebased on the latest kexec-tools and is available from the xen-v3 branch of: http://xenbits.xen.org/gitweb/?p=people/dvrabel/kexec-tools.git;a=summary Changes since v3: - Use paddr_t and page_to_maddr() etc. for portability. - Add explicit padding to hypercall structures where required. - Minor cleanup of the kexec_reloc assembly. - Print a message before exec'ing a crash image. - Style fixes (tabs, trailing whitespace) and typos. - Fix a bug where using the V1 interface and unloading a image may crash. Changes since v2: - Provide old struct xen_kexec_load if __XEN_INTERFACE_VERSION__ < 4.3 - Adjust new struct xen_kexec_load to avoid unnecessary padding. - Use domheap pages for the image and control pages. - Remove the DBG() macros from the reloc code. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-16 17:13 [PATCHv4 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel @ 2013-04-16 17:13 ` David Vrabel 2013-04-17 12:51 ` Daniel Kiper 0 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-16 17:13 UTC (permalink / raw) To: xen-devel; +Cc: kexec, Daniel Kiper, Keir Fraser, David Vrabel From: David Vrabel <david.vrabel@citrix.com> In the existing kexec hypercall, the load and unload ops depend on internals of the Linux kernel (the page list and code page provided by the kernel). The code page is used to transition between Xen context and the image so using kernel code doesn't make sense and will not work for PVH guests. Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops that no longer require a code page to be provided by the guest -- Xen now provides the code for calling the image directly. The new load op looks similar to the Linux kexec_load system call and allows the guest to provide the image data to be loaded. The guest specifies the architecture of the image which may be a 32-bit subarch of the hypervisor's architecture (i.e., an EM_386 image on an EM_X86_64 hypervisor). The toolstack can now load images without kernel involvement. This is required for supporting kexec when using a dom0 with an upstream kernel. Crash images are copied directly into the crash region on load. Default images are copied into domheap pages and a list of source and destination machine addresses is created. This is list is used in kexec_reloc() to relocate the image to its destination. The old load and unload sub-ops are still available (as KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top of the new infrastructure. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- xen/arch/x86/machine_kexec.c | 282 +++++++++++++++++++------ xen/arch/x86/x86_64/Makefile | 2 +- xen/arch/x86/x86_64/compat_kexec.S | 187 ---------------- xen/arch/x86/x86_64/kexec_reloc.S | 203 ++++++++++++++++++ xen/common/kexec.c | 397 +++++++++++++++++++++++++++++------ xen/common/kimage.c | 103 +++++++++ xen/include/asm-x86/fixmap.h | 3 - xen/include/asm-x86/machine_kexec.h | 14 ++ xen/include/xen/kexec.h | 14 +- xen/include/xen/kimage.h | 6 + 10 files changed, 879 insertions(+), 332 deletions(-) delete mode 100644 xen/arch/x86/x86_64/compat_kexec.S create mode 100644 xen/arch/x86/x86_64/kexec_reloc.S create mode 100644 xen/include/asm-x86/machine_kexec.h diff --git a/xen/arch/x86/machine_kexec.c b/xen/arch/x86/machine_kexec.c index 68b9705..a958316 100644 --- a/xen/arch/x86/machine_kexec.c +++ b/xen/arch/x86/machine_kexec.c @@ -1,9 +1,18 @@ /****************************************************************************** * machine_kexec.c * + * Copyright (C) 2013 Citrix Systems R&D Ltd. + * + * Portions derived from Linux's arch/x86/kernel/machine_kexec_64.c. + * + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> + * * Xen port written by: * - Simon 'Horms' Horman <horms@verge.net.au> * - Magnus Damm <magnus@valinux.co.jp> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. */ #include <xen/types.h> @@ -11,63 +20,216 @@ #include <xen/guest_access.h> #include <asm/fixmap.h> #include <asm/hpet.h> +#include <asm/page.h> +#include <asm/machine_kexec.h> + +static void init_level2_page(l2_pgentry_t *l2, unsigned long addr) +{ + unsigned long end_addr; + + addr &= PAGE_MASK; + end_addr = addr + L2_PAGETABLE_ENTRIES * (1ul << L2_PAGETABLE_SHIFT); -typedef void (*relocate_new_kernel_t)( - unsigned long indirection_page, - unsigned long *page_list, - unsigned long start_address, - unsigned int preserve_context); + while ( addr < end_addr ) + { + l2e_write(l2++, l2e_from_paddr(addr, __PAGE_HYPERVISOR | _PAGE_PSE)); -int machine_kexec_load(int type, int slot, xen_kexec_image_t *image) + addr += 1ul << L2_PAGETABLE_SHIFT; + } +} + +static int init_level3_page(struct kexec_image *image, l3_pgentry_t *l3, + unsigned long addr, unsigned long last_addr) { - unsigned long prev_ma = 0; - int fix_base = FIX_KEXEC_BASE_0 + (slot * (KEXEC_XEN_NO_PAGES >> 1)); - int k; + unsigned long end_addr; - /* setup fixmap to point to our pages and record the virtual address - * in every odd index in page_list[]. - */ + addr &= PAGE_MASK; + end_addr = addr + L3_PAGETABLE_ENTRIES * (1ul << L3_PAGETABLE_SHIFT); + + while( (addr < last_addr) && (addr < end_addr) ) + { + struct page_info *l2_page; + l2_pgentry_t *l2; + + l2_page = kimage_alloc_control_page(image, 0); + if ( !l2_page ) + return -ENOMEM; + l2 = __map_domain_page(l2_page); + init_level2_page(l2, addr); + unmap_domain_page(l2); + + l3e_write(l3++, l3e_from_page(l2_page, __PAGE_HYPERVISOR)); + + addr += 1ul << L3_PAGETABLE_SHIFT; + } + + return 0; +} + +/* + * Build a complete page table to identity map [addr, last_addr). + * + * Control pages are used so they do not overlap with the image source + * or destination. + */ +static int init_level4_page(struct kexec_image *image, l4_pgentry_t *l4, + unsigned long addr, unsigned long last_addr) +{ + unsigned long end_addr; + int result; + + addr &= PAGE_MASK; + end_addr = addr + L4_PAGETABLE_ENTRIES * (1ul << L4_PAGETABLE_SHIFT); + + while ( (addr < last_addr) && (addr < end_addr) ) + { + struct page_info *l3_page; + l3_pgentry_t *l3; + + l3_page = kimage_alloc_control_page(image, 0); + if ( !l3_page ) + return -ENOMEM; + l3 = __map_domain_page(l3_page); + result = init_level3_page(image, l3, addr, last_addr); + unmap_domain_page(l3); + if (result) + return result; + + l4e_write(l4++, l4e_from_page(l3_page, __PAGE_HYPERVISOR)); + + addr += 1ul << L4_PAGETABLE_SHIFT; + } + + return 0; +} + +/* + * Add a mapping for the control code page to the same virtual address + * as kexec_reloc. This allows us to keep running after these page + * tables are loaded in kexec_reloc. + * + * We don't really need to allocate control pages here as these + * entries won't be used while the kexec image is being copied, but it + * makes clean-up easier. + */ +static int init_transition_pgtable(struct kexec_image *image, l4_pgentry_t *l4) +{ + struct page_info *l3_page; + struct page_info *l2_page; + struct page_info *l1_page; + unsigned long vaddr, paddr; + l3_pgentry_t *l3 = NULL; + l2_pgentry_t *l2 = NULL; + l1_pgentry_t *l1 = NULL; + int ret = -ENOMEM; + + vaddr = (unsigned long)kexec_reloc; + paddr = page_to_maddr(image->control_code_page); + + l4 += l4_table_offset(vaddr); + if ( !(l4e_get_flags(*l4) & _PAGE_PRESENT) ) + { + l3_page = kimage_alloc_control_page(image, 0); + if ( !l3_page ) + goto out; + l4e_write(l4, l4e_from_page(l3_page, __PAGE_HYPERVISOR)); + } + else + l3_page = l4e_get_page(*l4); + + l3 = __map_domain_page(l3_page); + l3 += l3_table_offset(vaddr); + if ( !(l3e_get_flags(*l3) & _PAGE_PRESENT) ) + { + l2_page = kimage_alloc_control_page(image, 0); + if ( !l2_page ) + goto out; + l3e_write(l3, l3e_from_page(l2_page, __PAGE_HYPERVISOR)); + } + else + l2_page = l3e_get_page(*l3); + + l2 = __map_domain_page(l2_page); + l2 += l2_table_offset(vaddr); + if ( !(l2e_get_flags(*l2) & _PAGE_PRESENT) ) + { + l1_page = kimage_alloc_control_page(image, 0); + if ( !l1_page ) + goto out; + l2e_write(l2, l2e_from_page(l1_page, __PAGE_HYPERVISOR)); + } + else + l1_page = l2e_get_page(*l2); + + l1 = __map_domain_page(l1_page); + l1 += l1_table_offset(vaddr); + l1e_write(l1, l1e_from_pfn(paddr >> PAGE_SHIFT, __PAGE_HYPERVISOR)); + + ret = 0; +out: + if ( l1 ) + unmap_domain_page(l1); + if ( l2 ) + unmap_domain_page(l2); + if ( l3 ) + unmap_domain_page(l3); + return ret; +} - for ( k = 0; k < KEXEC_XEN_NO_PAGES; k++ ) + +static int build_reloc_page_table(struct kexec_image *image) +{ + struct page_info *l4_page; + l4_pgentry_t *l4; + int result; + + l4_page = kimage_alloc_control_page(image, 0); + if ( !l4_page ) + return -ENOMEM; + l4 = __map_domain_page(l4_page); + + result = init_level4_page(image, l4, 0, max_page << PAGE_SHIFT); + if ( result == 0) + result = init_transition_pgtable(image, l4); + unmap_domain_page(l4); + if ( result ) + return result; + + image->aux_page = l4_page; + return 0; +} + +int machine_kexec_load(struct kexec_image *image) +{ + void *code_page; + int ret; + + switch ( image->arch ) { - if ( (k & 1) == 0 ) - { - /* Even pages: machine address. */ - prev_ma = image->page_list[k]; - } - else - { - /* Odd pages: va for previous ma. */ - if ( is_pv_32on64_domain(dom0) ) - { - /* - * The compatability bounce code sets up a page table - * with a 1-1 mapping of the first 1G of memory so - * VA==PA here. - * - * This Linux purgatory code still sets up separate - * high and low mappings on the control page (entries - * 0 and 1) but it is harmless if they are equal since - * that PT is not live at the time. - */ - image->page_list[k] = prev_ma; - } - else - { - set_fixmap(fix_base + (k >> 1), prev_ma); - image->page_list[k] = fix_to_virt(fix_base + (k >> 1)); - } - } + case EM_386: + case EM_X86_64: + break; + default: + return -EINVAL; } + code_page = __map_domain_page(image->control_code_page); + memcpy(code_page, kexec_reloc, PAGE_SIZE); + unmap_domain_page(code_page); + + ret = build_reloc_page_table(image); + if ( ret < 0 ) + return ret; + return 0; } -void machine_kexec_unload(int type, int slot, xen_kexec_image_t *image) +void machine_kexec_unload(struct kexec_image *image) { + /* no-op. kimage_free() frees all control pages. */ } -void machine_reboot_kexec(xen_kexec_image_t *image) +void machine_reboot_kexec(struct kexec_image *image) { BUG_ON(smp_processor_id() != 0); smp_send_stop(); @@ -75,13 +237,10 @@ void machine_reboot_kexec(xen_kexec_image_t *image) BUG(); } -void machine_kexec(xen_kexec_image_t *image) +void machine_kexec(struct kexec_image *image) { - struct desc_ptr gdt_desc = { - .base = (unsigned long)(boot_cpu_gdt_table - FIRST_RESERVED_GDT_ENTRY), - .limit = LAST_RESERVED_GDT_BYTE - }; int i; + unsigned long reloc_flags = 0; /* We are about to permenantly jump out of the Xen context into the kexec * purgatory code. We really dont want to be still servicing interupts. @@ -109,29 +268,12 @@ void machine_kexec(xen_kexec_image_t *image) * not like running with NMIs disabled. */ enable_nmis(); - /* - * compat_machine_kexec() returns to idle pagetables, which requires us - * to be running on a static GDT mapping (idle pagetables have no GDT - * mappings in their per-domain mapping area). - */ - asm volatile ( "lgdt %0" : : "m" (gdt_desc) ); + if ( image->arch == EM_386 ) + reloc_flags |= KEXEC_RELOC_FLAG_COMPAT; - if ( is_pv_32on64_domain(dom0) ) - { - compat_machine_kexec(image->page_list[1], - image->indirection_page, - image->page_list, - image->start_address); - } - else - { - relocate_new_kernel_t rnk; - - rnk = (relocate_new_kernel_t) image->page_list[1]; - (*rnk)(image->indirection_page, image->page_list, - image->start_address, - 0 /* preserve_context */); - } + kexec_reloc(page_to_maddr(image->control_code_page), + page_to_maddr(image->aux_page), + image->head, image->entry_maddr, reloc_flags); } int machine_kexec_get(xen_kexec_range_t *range) diff --git a/xen/arch/x86/x86_64/Makefile b/xen/arch/x86/x86_64/Makefile index d56e12d..7f8fb3d 100644 --- a/xen/arch/x86/x86_64/Makefile +++ b/xen/arch/x86/x86_64/Makefile @@ -11,11 +11,11 @@ obj-y += mmconf-fam10h.o obj-y += mmconfig_64.o obj-y += mmconfig-shared.o obj-y += compat.o -obj-bin-y += compat_kexec.o obj-y += domain.o obj-y += physdev.o obj-y += platform_hypercall.o obj-y += cpu_idle.o obj-y += cpufreq.o +obj-bin-y += kexec_reloc.o obj-$(crash_debug) += gdbstub.o diff --git a/xen/arch/x86/x86_64/compat_kexec.S b/xen/arch/x86/x86_64/compat_kexec.S deleted file mode 100644 index fc92af9..0000000 --- a/xen/arch/x86/x86_64/compat_kexec.S +++ /dev/null @@ -1,187 +0,0 @@ -/* - * Compatibility kexec handler. - */ - -/* - * NOTE: We rely on Xen not relocating itself above the 4G boundary. This is - * currently true but if it ever changes then compat_pg_table will - * need to be moved back below 4G at run time. - */ - -#include <xen/config.h> - -#include <asm/asm_defns.h> -#include <asm/msr.h> -#include <asm/page.h> - -/* The unrelocated physical address of a symbol. */ -#define SYM_PHYS(sym) ((sym) - __XEN_VIRT_START) - -/* Load physical address of symbol into register and relocate it. */ -#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ - add xen_phys_start(%rip), reg - -/* - * Relocate a physical address in memory. Size of temporary register - * determines size of the value to relocate. - */ -#define RELOCATE_MEM(addr,reg) mov addr(%rip), reg ; \ - add xen_phys_start(%rip), reg ; \ - mov reg, addr(%rip) - - .text - - .code64 - -ENTRY(compat_machine_kexec) - /* x86/64 x86/32 */ - /* %rdi - relocate_new_kernel_t CALL */ - /* %rsi - indirection page 4(%esp) */ - /* %rdx - page_list 8(%esp) */ - /* %rcx - start address 12(%esp) */ - /* cpu has pae 16(%esp) */ - - /* Shim the 64 bit page_list into a 32 bit page_list. */ - mov $12,%r9 - lea compat_page_list(%rip), %rbx -1: dec %r9 - movl (%rdx,%r9,8),%eax - movl %eax,(%rbx,%r9,4) - test %r9,%r9 - jnz 1b - - RELOCATE_SYM(compat_page_list,%rdx) - - /* Relocate compatibility mode entry point address. */ - RELOCATE_MEM(compatibility_mode_far,%eax) - - /* Relocate compat_pg_table. */ - RELOCATE_MEM(compat_pg_table, %rax) - RELOCATE_MEM(compat_pg_table+0x8, %rax) - RELOCATE_MEM(compat_pg_table+0x10,%rax) - RELOCATE_MEM(compat_pg_table+0x18,%rax) - - /* - * Setup an identity mapped region in PML4[0] of idle page - * table. - */ - RELOCATE_SYM(l3_identmap,%rax) - or $0x63,%rax - mov %rax, idle_pg_table(%rip) - - /* Switch to idle page table. */ - RELOCATE_SYM(idle_pg_table,%rax) - movq %rax, %cr3 - - /* Switch to identity mapped compatibility stack. */ - RELOCATE_SYM(compat_stack,%rax) - movq %rax, %rsp - - /* Save xen_phys_start for 32 bit code. */ - movq xen_phys_start(%rip), %rbx - - /* Jump to low identity mapping in compatibility mode. */ - ljmp *compatibility_mode_far(%rip) - ud2 - -compatibility_mode_far: - .long SYM_PHYS(compatibility_mode) - .long __HYPERVISOR_CS32 - - /* - * We use 5 words of stack for the arguments passed to the kernel. The - * kernel only uses 1 word before switching to its own stack. Allocate - * 16 words to give "plenty" of room. - */ - .fill 16,4,0 -compat_stack: - - .code32 - -#undef RELOCATE_SYM -#undef RELOCATE_MEM - -/* - * Load physical address of symbol into register and relocate it. %rbx - * contains xen_phys_start(%rip) saved before jump to compatibility - * mode. - */ -#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ - add %ebx, reg - -compatibility_mode: - /* Setup some sane segments. */ - movl $__HYPERVISOR_DS32, %eax - movl %eax, %ds - movl %eax, %es - movl %eax, %fs - movl %eax, %gs - movl %eax, %ss - - /* Push arguments onto stack. */ - pushl $0 /* 20(%esp) - preserve context */ - pushl $1 /* 16(%esp) - cpu has pae */ - pushl %ecx /* 12(%esp) - start address */ - pushl %edx /* 8(%esp) - page list */ - pushl %esi /* 4(%esp) - indirection page */ - pushl %edi /* 0(%esp) - CALL */ - - /* Disable paging and therefore leave 64 bit mode. */ - movl %cr0, %eax - andl $~X86_CR0_PG, %eax - movl %eax, %cr0 - - /* Switch to 32 bit page table. */ - RELOCATE_SYM(compat_pg_table, %eax) - movl %eax, %cr3 - - /* Clear MSR_EFER[LME], disabling long mode */ - movl $MSR_EFER,%ecx - rdmsr - btcl $_EFER_LME,%eax - wrmsr - - /* Re-enable paging, but only 32 bit mode now. */ - movl %cr0, %eax - orl $X86_CR0_PG, %eax - movl %eax, %cr0 - jmp 1f -1: - - popl %eax - call *%eax - ud2 - - .data - .align 4 -compat_page_list: - .fill 12,4,0 - - .align 32,0 - - /* - * These compat page tables contain an identity mapping of the - * first 4G of the physical address space. - */ -compat_pg_table: - .long SYM_PHYS(compat_pg_table_l2) + 0*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 1*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 2*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 3*PAGE_SIZE + 0x01, 0 - - .section .data.page_aligned, "aw", @progbits - .align PAGE_SIZE,0 -compat_pg_table_l2: - .macro identmap from=0, count=512 - .if \count-1 - identmap "(\from+0)","(\count/2)" - identmap "(\from+(0x200000*(\count/2)))","(\count/2)" - .else - .quad 0x00000000000000e3 + \from - .endif - .endm - - identmap 0x00000000 - identmap 0x40000000 - identmap 0x80000000 - identmap 0xc0000000 diff --git a/xen/arch/x86/x86_64/kexec_reloc.S b/xen/arch/x86/x86_64/kexec_reloc.S new file mode 100644 index 0000000..f9e8ac9 --- /dev/null +++ b/xen/arch/x86/x86_64/kexec_reloc.S @@ -0,0 +1,203 @@ +/* + * Relocate a kexec_image to its destination and call it. + * + * Copyright (C) 2013 Citrix Systems R&D Ltd. + * + * Portions derived from Linux's arch/x86/kernel/relocate_kernel_64.S. + * + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ +#include <xen/config.h> + +#include <asm/asm_defns.h> +#include <asm/msr.h> +#include <asm/page.h> +#include <asm/machine_kexec.h> + + .text + .align PAGE_SIZE + .code64 + +ENTRY(kexec_reloc) + /* %rdi - code page maddr */ + /* %rsi - page table maddr */ + /* %rdx - indirection page maddr */ + /* %rcx - entry maddr */ + /* %r8 - flags */ + + movq %rdx, %rbx + + /* Setup stack. */ + leaq (reloc_stack - kexec_reloc)(%rdi), %rsp + + /* Load reloc page table. */ + movq %rsi, %cr3 + + /* Jump to identity mapped code. */ + leaq (identity_mapped - kexec_reloc)(%rdi), %rax + jmpq *%rax + +identity_mapped: + pushq %rcx + pushq %rbx + pushq %rsi + pushq %rdi + + /* + * Set cr0 to a known state: + * - Paging enabled + * - Alignment check disabled + * - Write protect disabled + * - No task switch + * - Don't do FP software emulation. + * - Proctected mode enabled + */ + movq %cr0, %rax + andq $~(X86_CR0_AM | X86_CR0_WP | X86_CR0_TS | X86_CR0_EM), %rax + orl $(X86_CR0_PG | X86_CR0_PE), %eax + movq %rax, %cr0 + + /* + * Set cr4 to a known state: + * - physical address extension enabled + */ + movq $X86_CR4_PAE, %rax + movq %rax, %cr4 + + movq %rbx, %rdi + call relocate_pages + + popq %rdi + popq %rsi + popq %rbx + popq %rcx + + /* Need to switch to 32-bit mode? */ + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 + jnz call_32_bit + +call_64_bit: + /* Call the image entry point. This should never return. */ + call *%rcx + ud2 + +call_32_bit: + /* Setup IDT. */ + lidt compat_mode_idt(%rip) + + /* Load compat GDT. */ + leaq (compat_mode_gdt - kexec_reloc)(%rdi), %rax + movq %rax, (compat_mode_gdt_desc + 2)(%rip) + lgdt compat_mode_gdt_desc(%rip) + + /* Relocate compatibility mode entry point address. */ + leal (compatibility_mode - kexec_reloc)(%edi), %eax + movl %eax, compatibility_mode_far(%rip) + + /* Enter compatibility mode. */ + ljmp *compatibility_mode_far(%rip) + +relocate_pages: + /* %rdi - indirection page maddr */ + cld + movq %rdi, %rcx + xorq %rdi, %rdi + xorq %rsi, %rsi + jmp 1f + +0: /* top, read another word for the indirection page */ + + movq (%rbx), %rcx + addq $8, %rbx +1: + testq $0x1, %rcx /* is it a destination page? */ + jz 2f + movq %rcx, %rdi + andq $0xfffffffffffff000, %rdi + jmp 0b +2: + testq $0x2, %rcx /* is it an indirection page? */ + jz 2f + movq %rcx, %rbx + andq $0xfffffffffffff000, %rbx + jmp 0b +2: + testq $0x4, %rcx /* is it the done indicator? */ + jz 2f + jmp 3f +2: + testq $0x8, %rcx /* is it the source indicator? */ + jz 0b /* Ignore it otherwise */ + movq %rcx, %rsi /* For ever source page do a copy */ + andq $0xfffffffffffff000, %rsi + + movq $512, %rcx + rep movsq + + jmp 0b +3: + ret + + .code32 + +compatibility_mode: + /* Setup some sane segments. */ + movl $0x0008, %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %fs + movl %eax, %gs + movl %eax, %ss + + movl %ecx, %ebp + + /* Disable paging and therefore leave 64 bit mode. */ + movl %cr0, %eax + andl $~X86_CR0_PG, %eax + movl %eax, %cr0 + + /* Disable long mode */ + movl $MSR_EFER, %ecx + rdmsr + andl $~EFER_LME, %eax + wrmsr + + /* Clear cr4 to disable PAE. */ + movl $0, %eax + movl %eax, %cr4 + + /* Call the image entry point. This should never return. */ + call *%ebp + ud2 + + .align 16 +compatibility_mode_far: + .long 0x00000000 /* set in call_32_bit above */ + .word 0x0010 + + .align 16 +compat_mode_gdt_desc: + .word (3*8)-1 + .quad 0x0000000000000000 /* set in call_32_bit above */ + + .align 16 +compat_mode_gdt: + .quad 0x0000000000000000 /* null */ + .quad 0x00cf92000000ffff /* 0x0008 ring 0 data */ + .quad 0x00cf9a000000ffff /* 0x0010 ring 0 code, compatibility */ + +compat_mode_idt: + .word 0 /* limit */ + .long 0 /* base */ + + /* + * 16 words of stack are more than enough. + */ + .fill 16,8,0 +reloc_stack: + + .globl kexec_reloc_size + .set kexec_reloc_size, . - kexec_reloc diff --git a/xen/common/kexec.c b/xen/common/kexec.c index 2d34524..9e2f2b3 100644 --- a/xen/common/kexec.c +++ b/xen/common/kexec.c @@ -25,6 +25,7 @@ #include <xen/version.h> #include <xen/console.h> #include <xen/kexec.h> +#include <xen/kimage.h> #include <public/elfnote.h> #include <xsm/xsm.h> #include <xen/cpu.h> @@ -47,7 +48,7 @@ static Elf_Note *xen_crash_note; static cpumask_t crash_saved_cpus; -static xen_kexec_image_t kexec_image[KEXEC_IMAGE_NR]; +static struct kexec_image *kexec_image[KEXEC_IMAGE_NR]; #define KEXEC_FLAG_DEFAULT_POS (KEXEC_IMAGE_NR + 0) #define KEXEC_FLAG_CRASH_POS (KEXEC_IMAGE_NR + 1) @@ -311,14 +312,14 @@ void kexec_crash(void) kexec_common_shutdown(); kexec_crash_save_cpu(); machine_crash_shutdown(); - machine_kexec(&kexec_image[KEXEC_IMAGE_CRASH_BASE + pos]); + machine_kexec(kexec_image[KEXEC_IMAGE_CRASH_BASE + pos]); BUG(); } static long kexec_reboot(void *_image) { - xen_kexec_image_t *image = _image; + struct kexec_image *image = _image; kexecing = TRUE; @@ -734,63 +735,265 @@ static void crash_save_vmcoreinfo(void) #endif } -static int kexec_load_unload_internal(unsigned long op, xen_kexec_load_v1_t *load) +static void kexec_unload_image(struct kexec_image *image) +{ + if ( !image ) + return; + + machine_kexec_unload(image); + kimage_free(image); +} + +static int kexec_exec(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_exec_t exec; + struct kexec_image *image; + int base, bit, pos, ret = -EINVAL; + + if ( unlikely(copy_from_guest(&exec, uarg, 1)) ) + return -EFAULT; + + if ( kexec_load_get_bits(exec.type, &base, &bit) ) + return -EINVAL; + + pos = (test_bit(bit, &kexec_flags) != 0); + + /* Only allow kexec/kdump into loaded images */ + if ( !test_bit(base + pos, &kexec_flags) ) + return -ENOENT; + + switch (exec.type) + { + case KEXEC_TYPE_DEFAULT: + image = kexec_image[base + pos]; + ret = continue_hypercall_on_cpu(0, kexec_reboot, image); + break; + case KEXEC_TYPE_CRASH: + kexec_crash(); /* Does not return */ + break; + } + + return -EINVAL; /* never reached */ +} + +static int kexec_swap_images(int type, struct kexec_image *new, + struct kexec_image **old) { - xen_kexec_image_t *image; int base, bit, pos; - int ret = 0; + int new_slot, old_slot; + + *old = NULL; + + spin_lock(&kexec_lock); + + if ( test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags) ) + { + spin_unlock(&kexec_lock); + return -EBUSY; + } - if ( kexec_load_get_bits(load->type, &base, &bit) ) + if ( kexec_load_get_bits(type, &base, &bit) ) return -EINVAL; pos = (test_bit(bit, &kexec_flags) != 0); + old_slot = base + pos; + new_slot = base + !pos; - /* Load the user data into an unused image */ - if ( op == KEXEC_CMD_kexec_load ) + if ( new ) { - image = &kexec_image[base + !pos]; + kexec_image[new_slot] = new; + set_bit(new_slot, &kexec_flags); + } + change_bit(bit, &kexec_flags); - BUG_ON(test_bit((base + !pos), &kexec_flags)); /* must be free */ + clear_bit(old_slot, &kexec_flags); + *old = kexec_image[old_slot]; - memcpy(image, &load->image, sizeof(*image)); + spin_unlock(&kexec_lock); - if ( !(ret = machine_kexec_load(load->type, base + !pos, image)) ) - { - /* Set image present bit */ - set_bit((base + !pos), &kexec_flags); + return 0; +} - /* Make new image the active one */ - change_bit(bit, &kexec_flags); - } +static int kexec_load_slot(struct kexec_image *kimage) +{ + struct kexec_image *old_kimage; + int ret = -ENOMEM; + + ret = machine_kexec_load(kimage); + if ( ret < 0 ) + goto error; + + crash_save_vmcoreinfo(); + + ret = kexec_swap_images(kimage->type, kimage, &old_kimage); + if ( ret < 0 ) + goto error; + + kexec_unload_image(old_kimage); + + return 0; + +error: + kimage_free(kimage); + return ret; +} + +static uint16_t kexec_load_v1_arch(void) +{ +#ifdef CONFIG_X86 + return is_pv_32on64_domain(dom0) ? EM_386 : EM_X86_64; +#else + return EM_NONE; +#endif +} + +static int kexec_segments_add_segment( + unsigned *nr_segments, xen_kexec_segment_t *segments, + unsigned long mfn) +{ + paddr_t maddr = (paddr_t)mfn << PAGE_SHIFT; + int n = *nr_segments; - crash_save_vmcoreinfo(); + /* Need a new segment? */ + if ( n == 0 + || segments[n-1].dest_maddr + segments[n-1].dest_size != maddr ) + { + n++; + if ( n > KEXEC_SEGMENT_MAX ) + return -EINVAL; + *nr_segments = n; + + set_xen_guest_handle(segments[n-1].buf, NULL); + segments[n-1].buf_size = 0; + segments[n-1].dest_maddr = maddr; + segments[n-1].dest_size = 0; } - /* Unload the old image if present and load successful */ - if ( ret == 0 && !test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags) ) + return 0; +} + +static int kexec_segments_from_ind_page(unsigned long mfn, + unsigned *nr_segments, + xen_kexec_segment_t *segments, + bool_t compat) +{ + void *page; + kimage_entry_t *entry; + int ret = 0; + + page = map_domain_page(mfn); + + /* + * Walk the indirection page list, adding destination pages to the + * segments. + */ + for ( entry = page; ; ) { - if ( test_and_clear_bit((base + pos), &kexec_flags) ) + unsigned long ind; + + ind = kimage_entry_ind(entry, compat); + mfn = kimage_entry_mfn(entry, compat); + + switch ( ind ) { - image = &kexec_image[base + pos]; - machine_kexec_unload(load->type, base + pos, image); + case IND_DESTINATION: + ret = kexec_segments_add_segment(nr_segments, segments, mfn); + if ( ret < 0 ) + goto done; + break; + case IND_INDIRECTION: + unmap_domain_page(page); + page = map_domain_page(mfn); + if ( page == NULL ) + return -ENOMEM; + entry = page; + continue; + case IND_DONE: + goto done; + case IND_SOURCE: + segments[*nr_segments-1].dest_size += PAGE_SIZE; + break; + default: + ret = -EINVAL; + goto done; } + entry = kimage_entry_next(entry, compat); } +done: + unmap_domain_page(page); + return ret; +} + +static int kexec_do_load_v1(xen_kexec_load_v1_t *load, int compat) +{ + struct kexec_image *kimage = NULL; + xen_kexec_segment_t *segments; + uint16_t arch; + unsigned nr_segments = 0; + unsigned long ind_mfn = load->image.indirection_page >> PAGE_SHIFT; + int ret; + + arch = kexec_load_v1_arch(); + if ( arch == EM_NONE ) + return -ENOSYS; + + segments = xmalloc_array(xen_kexec_segment_t, KEXEC_SEGMENT_MAX); + if ( segments == NULL ) + return -ENOMEM; + + /* + * Work out the image segments (destination only) from the + * indirection pages. + * + * This is needed so we don't allocate pages that will overlap + * with the destination when building the new set of indirection + * pages below. + */ + ret = kexec_segments_from_ind_page(ind_mfn, &nr_segments, segments, compat); + if ( ret < 0 ) + goto error; + + ret = kimage_alloc(&kimage, load->type, arch, load->image.start_address, + nr_segments, segments); + if ( ret < 0 ) + goto error; + + /* + * Build a new set of indirection pages in the native format. + * + * This walks the guest provided indirection pages a second time. + * The guest could have altered then, invalidating the segment + * information constructed above. This will only result in the + * resulting image being potentially unrelocatable. + */ + ret = kimage_build_ind(kimage, ind_mfn, compat); + if ( ret < 0 ) + goto error; + + ret = kexec_load_slot(kimage); + if ( ret < 0 ) + goto error; + return 0; + +error: + if ( !kimage ) + xfree(segments); + kimage_free(kimage); return ret; } -static int kexec_load_unload(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load_v1(XEN_GUEST_HANDLE_PARAM(void) uarg) { xen_kexec_load_v1_t load; if ( unlikely(copy_from_guest(&load, uarg, 1)) ) return -EFAULT; - return kexec_load_unload_internal(op, &load); + return kexec_do_load_v1(&load, 0); } -static int kexec_load_unload_compat(unsigned long op, - XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) { #ifdef CONFIG_COMPAT compat_kexec_load_v1_t compat_load; @@ -809,49 +1012,113 @@ static int kexec_load_unload_compat(unsigned long op, load.type = compat_load.type; XLAT_kexec_image(&load.image, &compat_load.image); - return kexec_load_unload_internal(op, &load); -#else /* CONFIG_COMPAT */ + return kexec_do_load_v1(&load, 1); +#else return 0; -#endif /* CONFIG_COMPAT */ +#endif } -static int kexec_exec(XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load(XEN_GUEST_HANDLE_PARAM(void) uarg) { - xen_kexec_exec_t exec; - xen_kexec_image_t *image; - int base, bit, pos, ret = -EINVAL; + xen_kexec_load_t load; + xen_kexec_segment_t *segments; + struct kexec_image *kimage = NULL; + int ret; - if ( unlikely(copy_from_guest(&exec, uarg, 1)) ) + if ( copy_from_guest(&load, uarg, 1) ) return -EFAULT; - if ( kexec_load_get_bits(exec.type, &base, &bit) ) + if ( load.nr_segments >= KEXEC_SEGMENT_MAX ) return -EINVAL; - pos = (test_bit(bit, &kexec_flags) != 0); - - /* Only allow kexec/kdump into loaded images */ - if ( !test_bit(base + pos, &kexec_flags) ) - return -ENOENT; + segments = xmalloc_array(xen_kexec_segment_t, load.nr_segments); + if ( segments == NULL ) + return -ENOMEM; - switch (exec.type) + if ( copy_from_guest(segments, load.segments, load.nr_segments) ) { - case KEXEC_TYPE_DEFAULT: - image = &kexec_image[base + pos]; - ret = continue_hypercall_on_cpu(0, kexec_reboot, image); - break; - case KEXEC_TYPE_CRASH: - kexec_crash(); /* Does not return */ - break; + ret = -EFAULT; + goto error; } - return -EINVAL; /* never reached */ + ret = kimage_alloc(&kimage, load.type, load.arch, load.entry_maddr, + load.nr_segments, segments); + if ( ret < 0 ) + goto error; + + ret = kimage_load_segments(kimage); + if ( ret < 0 ) + goto error; + + ret = kexec_load_slot(kimage); + if ( ret < 0 ) + goto error; + + return 0; + +error: + if ( ! kimage ) + xfree(segments); + kimage_free(kimage); + return ret; +} + +static int kexec_do_unload(xen_kexec_unload_t *unload) +{ + struct kexec_image *old_kimage; + int ret; + + ret = kexec_swap_images(unload->type, NULL, &old_kimage); + if ( ret < 0 ) + return ret; + + kexec_unload_image(old_kimage); + + return 0; +} + +static int kexec_unload_v1(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_load_v1_t load; + xen_kexec_unload_t unload; + + if ( copy_from_guest(&load, uarg, 1) ) + return -EFAULT; + + unload.type = load.type; + return kexec_do_unload(&unload); +} + +static int kexec_unload_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ +#ifdef CONFIG_COMPAT + compat_kexec_load_v1_t compat_load; + xen_kexec_unload_t unload; + + if ( copy_from_guest(&compat_load, uarg, 1) ) + return -EFAULT; + + unload.type = compat_load.type; + return kexec_do_unload(&unload); +#else + return 0; +#endif +} + +static int kexec_unload(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_unload_t unload; + + if ( unlikely(copy_from_guest(&unload, uarg, 1)) ) + return -EFAULT; + + return kexec_do_unload(&unload); } static int do_kexec_op_internal(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg, bool_t compat) { - unsigned long flags; int ret = -EINVAL; ret = xsm_kexec(XSM_PRIV); @@ -867,20 +1134,26 @@ static int do_kexec_op_internal(unsigned long op, ret = kexec_get_range(uarg); break; case KEXEC_CMD_kexec_load_v1: + if ( compat ) + ret = kexec_load_v1_compat(uarg); + else + ret = kexec_load_v1(uarg); + break; case KEXEC_CMD_kexec_unload_v1: - spin_lock_irqsave(&kexec_lock, flags); - if (!test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags)) - { - if (compat) - ret = kexec_load_unload_compat(op, uarg); - else - ret = kexec_load_unload(op, uarg); - } - spin_unlock_irqrestore(&kexec_lock, flags); + if ( compat ) + ret = kexec_unload_v1_compat(uarg); + else + ret = kexec_unload_v1(uarg); break; case KEXEC_CMD_kexec: ret = kexec_exec(uarg); break; + case KEXEC_CMD_kexec_load: + ret = kexec_load(uarg); + break; + case KEXEC_CMD_kexec_unload: + ret = kexec_unload(uarg); + break; } return ret; diff --git a/xen/common/kimage.c b/xen/common/kimage.c index a478aab..86261ca 100644 --- a/xen/common/kimage.c +++ b/xen/common/kimage.c @@ -812,6 +812,109 @@ int kimage_load_segments(struct kexec_image *image) return 0; } +kimage_entry_t *kimage_entry_next(kimage_entry_t *entry, bool_t compat) +{ + if ( compat ) + return (kimage_entry_t *)((uint32_t *)entry + 1); + return entry + 1; +} + +unsigned long kimage_entry_mfn(kimage_entry_t *entry, bool_t compat) +{ + if ( compat ) + return *(uint32_t *)entry >> PAGE_SHIFT; + return *entry >> PAGE_SHIFT; +} + +unsigned long kimage_entry_ind(kimage_entry_t *entry, bool_t compat) +{ + if ( compat ) + return *(uint32_t *)entry & 0xf; + return *entry & 0xf; +} + +int kimage_build_ind(struct kexec_image *image, unsigned long ind_mfn, + bool_t compat) +{ + void *page; + kimage_entry_t *entry; + int ret = 0; + paddr_t dest = KIMAGE_NO_DEST; + + page = map_domain_page(ind_mfn); + if ( page == NULL ) + return -ENOMEM; + + /* + * Walk the guest-supplied indirection pages, adding entries to + * the image's indirection pages. + */ + for ( entry = page; ; ) + { + unsigned long ind; + unsigned long mfn; + + ind = kimage_entry_ind(entry, compat); + mfn = kimage_entry_mfn(entry, compat); + + switch ( ind ) + { + case IND_DESTINATION: + dest = (paddr_t)mfn << PAGE_SHIFT; + ret = kimage_set_destination(image, dest); + if ( ret < 0 ) + goto done; + break; + case IND_INDIRECTION: + unmap_domain_page(page); + page = map_domain_page(mfn); + entry = page; + continue; + case IND_DONE: + kimage_terminate(image); + goto done; + case IND_SOURCE: + { + struct page_info *guest_page, *xen_page; + + guest_page = mfn_to_page(mfn); + if ( !get_page(guest_page, current->domain) ) + { + ret = -EFAULT; + goto done; + } + + xen_page = kimage_alloc_page(image, dest); + if ( !xen_page ) + { + put_page(guest_page); + ret = -ENOMEM; + goto done; + } + + copy_domain_page(page_to_mfn(xen_page), mfn); + put_page(guest_page); + + ret = kimage_add_page(image, page_to_maddr(xen_page)); + if ( ret < 0 ) + goto done; + dest += PAGE_SIZE; + break; + } + default: + ret = -EINVAL; + goto done; + } + entry = kimage_entry_next(entry, compat); + } +done: + unmap_domain_page(page); + return ret; +} + + + + /* * Local variables: * mode: C diff --git a/xen/include/asm-x86/fixmap.h b/xen/include/asm-x86/fixmap.h index 2eefcf4..1695228 100644 --- a/xen/include/asm-x86/fixmap.h +++ b/xen/include/asm-x86/fixmap.h @@ -57,9 +57,6 @@ enum fixed_addresses { FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1, FIX_HPET_BASE, FIX_CYCLONE_TIMER, - FIX_KEXEC_BASE_0, - FIX_KEXEC_BASE_END = FIX_KEXEC_BASE_0 \ - + ((KEXEC_XEN_NO_PAGES >> 1) * KEXEC_IMAGE_NR) - 1, FIX_IOMMU_REGS_BASE_0, FIX_IOMMU_REGS_END = FIX_IOMMU_REGS_BASE_0 + MAX_IOMMUS-1, FIX_IOMMU_MMIO_BASE_0, diff --git a/xen/include/asm-x86/machine_kexec.h b/xen/include/asm-x86/machine_kexec.h new file mode 100644 index 0000000..ec41099 --- /dev/null +++ b/xen/include/asm-x86/machine_kexec.h @@ -0,0 +1,14 @@ +#ifndef __X86_MACHINE_KEXEC_H__ +#define __X86_MACHINE_KEXEC_H__ + +#define KEXEC_RELOC_FLAG_COMPAT 0x1 /* 32-bit image */ + +#ifndef __ASSEMBLY__ + +extern void kexec_reloc(unsigned long reloc_code, unsigned long reloc_pt, + unsigned long ind_maddr, unsigned long entry_maddr, + unsigned long flags); + +#endif + +#endif /* __X86_MACHINE_KEXEC_H__ */ diff --git a/xen/include/xen/kexec.h b/xen/include/xen/kexec.h index 1a5dda1..7bb9213 100644 --- a/xen/include/xen/kexec.h +++ b/xen/include/xen/kexec.h @@ -6,6 +6,7 @@ #include <public/kexec.h> #include <asm/percpu.h> #include <xen/elfcore.h> +#include <xen/kimage.h> typedef struct xen_kexec_reserve { unsigned long size; @@ -40,11 +41,11 @@ extern enum low_crashinfo low_crashinfo_mode; extern paddr_t crashinfo_maxaddr_bits; void kexec_early_calculations(void); -int machine_kexec_load(int type, int slot, xen_kexec_image_t *image); -void machine_kexec_unload(int type, int slot, xen_kexec_image_t *image); +int machine_kexec_load(struct kexec_image *image); +void machine_kexec_unload(struct kexec_image *image); void machine_kexec_reserved(xen_kexec_reserve_t *reservation); -void machine_reboot_kexec(xen_kexec_image_t *image); -void machine_kexec(xen_kexec_image_t *image); +void machine_reboot_kexec(struct kexec_image *image); +void machine_kexec(struct kexec_image *image); void kexec_crash(void); void kexec_crash_save_cpu(void); crash_xen_info_t *kexec_crash_save_info(void); @@ -52,11 +53,6 @@ void machine_crash_shutdown(void); int machine_kexec_get(xen_kexec_range_t *range); int machine_kexec_get_xen(xen_kexec_range_t *range); -void compat_machine_kexec(unsigned long rnk, - unsigned long indirection_page, - unsigned long *page_list, - unsigned long start_address); - /* vmcoreinfo stuff */ #define VMCOREINFO_BYTES (4096) #define VMCOREINFO_NOTE_NAME "VMCOREINFO_XEN" diff --git a/xen/include/xen/kimage.h b/xen/include/xen/kimage.h index 0dbfe81..22ab5d7 100644 --- a/xen/include/xen/kimage.h +++ b/xen/include/xen/kimage.h @@ -45,6 +45,12 @@ int kimage_load_segments(struct kexec_image *image); struct page_info *kimage_alloc_control_page(struct kexec_image *image, unsigned memflags); +kimage_entry_t *kimage_entry_next(kimage_entry_t *entry, bool_t compat); +unsigned long kimage_entry_mfn(kimage_entry_t *entry, bool_t compat); +unsigned long kimage_entry_ind(kimage_entry_t *entry, bool_t compat); +int kimage_build_ind(struct kexec_image *image, unsigned long ind_mfn, + bool_t compat); + #endif /* __XEN_KIMAGE_H__ */ /* -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-16 17:13 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel @ 2013-04-17 12:51 ` Daniel Kiper 2013-04-18 16:29 ` David Vrabel 0 siblings, 1 reply; 34+ messages in thread From: Daniel Kiper @ 2013-04-17 12:51 UTC (permalink / raw) To: David Vrabel; +Cc: kexec, Keir Fraser, xen-devel On Tue, Apr 16, 2013 at 06:13:07PM +0100, David Vrabel wrote: > From: David Vrabel <david.vrabel@citrix.com> > > In the existing kexec hypercall, the load and unload ops depend on > internals of the Linux kernel (the page list and code page provided by > the kernel). The code page is used to transition between Xen context > and the image so using kernel code doesn't make sense and will not > work for PVH guests. > > Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops > that no longer require a code page to be provided by the guest -- Xen > now provides the code for calling the image directly. > > The new load op looks similar to the Linux kexec_load system call and > allows the guest to provide the image data to be loaded. The guest > specifies the architecture of the image which may be a 32-bit subarch > of the hypervisor's architecture (i.e., an EM_386 image on an > EM_X86_64 hypervisor). > > The toolstack can now load images without kernel involvement. This is > required for supporting kexec when using a dom0 with an upstream > kernel. > > Crash images are copied directly into the crash region on load. > Default images are copied into domheap pages and a list of source and > destination machine addresses is created. This is list is used in > kexec_reloc() to relocate the image to its destination. > > The old load and unload sub-ops are still available (as > KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top > of the new infrastructure. > > Signed-off-by: David Vrabel <david.vrabel@citrix.com> [...] > +int machine_kexec_load(struct kexec_image *image) > +{ > + void *code_page; > + int ret; > + > + switch ( image->arch ) > { > - if ( (k & 1) == 0 ) > - { > - /* Even pages: machine address. */ > - prev_ma = image->page_list[k]; > - } > - else > - { > - /* Odd pages: va for previous ma. */ > - if ( is_pv_32on64_domain(dom0) ) > - { > - /* > - * The compatability bounce code sets up a page table > - * with a 1-1 mapping of the first 1G of memory so > - * VA==PA here. > - * > - * This Linux purgatory code still sets up separate > - * high and low mappings on the control page (entries > - * 0 and 1) but it is harmless if they are equal since > - * that PT is not live at the time. > - */ > - image->page_list[k] = prev_ma; > - } > - else > - { > - set_fixmap(fix_base + (k >> 1), prev_ma); > - image->page_list[k] = fix_to_virt(fix_base + (k >> 1)); > - } > - } > + case EM_386: > + case EM_X86_64: > + break; > + default: > + return -EINVAL; > } > > + code_page = __map_domain_page(image->control_code_page); > + memcpy(code_page, kexec_reloc, PAGE_SIZE); memcpy(code_page, kexec_reloc, kexec_reloc_size); Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-17 12:51 ` Daniel Kiper @ 2013-04-18 16:29 ` David Vrabel 2013-04-19 8:08 ` Daniel Kiper 0 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-04-18 16:29 UTC (permalink / raw) To: Daniel Kiper Cc: kexec@lists.infradead.org, Keir (Xen.org), xen-devel@lists.xen.org On 17/04/13 13:51, Daniel Kiper wrote: > On Tue, Apr 16, 2013 at 06:13:07PM +0100, David Vrabel wrote: >> >> } >> >> + code_page = __map_domain_page(image->control_code_page); >> + memcpy(code_page, kexec_reloc, PAGE_SIZE); > > memcpy(code_page, kexec_reloc, kexec_reloc_size); kexec_reloc_size is absolute symbol and doing this give linker errors. FWIW, Linux also uses a #define'd value for its similar memcpy. I have added a link time check that kexec_reloc_size <= PAGE_SIZE. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-04-18 16:29 ` David Vrabel @ 2013-04-19 8:08 ` Daniel Kiper 0 siblings, 0 replies; 34+ messages in thread From: Daniel Kiper @ 2013-04-19 8:08 UTC (permalink / raw) To: David Vrabel Cc: kexec@lists.infradead.org, Keir (Xen.org), xen-devel@lists.xen.org On Thu, Apr 18, 2013 at 05:29:33PM +0100, David Vrabel wrote: > On 17/04/13 13:51, Daniel Kiper wrote: > > On Tue, Apr 16, 2013 at 06:13:07PM +0100, David Vrabel wrote: > >> > >> } > >> > >> + code_page = __map_domain_page(image->control_code_page); > >> + memcpy(code_page, kexec_reloc, PAGE_SIZE); > > > > memcpy(code_page, kexec_reloc, kexec_reloc_size); > > kexec_reloc_size is absolute symbol and doing this give linker errors. Yes, it should be changed to something like that: kexec_reloc_size: .long . - xen_relocate_kernel Somwhere in xen/include/asm-x86/machine_kexec.h: extern unsigned int kexec_reloc_size; > FWIW, Linux also uses a #define'd value for its similar memcpy. I saw that sometime ago and I think this is a bug. We should copy only kexec_reloc() code and nothing else. Otherwise we ask for problems. I am going to post relevant patches for this and others kexec issues found in Linux Kernel. > I have added a link time check that kexec_reloc_size <= PAGE_SIZE. Good idea but it should be kexec_reloc_size <= KEXEC_CONTROL_PAGE_SIZE. Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* [PATCH 0/8] kexec: extended kexec hypercall for use with pv-ops kernels @ 2013-02-21 17:48 David Vrabel 2013-02-21 17:48 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel 0 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-02-21 17:48 UTC (permalink / raw) To: xen-devel; +Cc: Daniel Kiper, kexec, David Vrabel The series improves the kexec hypercall by making Xen responsible for loading and relocating the image. This allows kexec to be usable by pv-ops kernels and should allow kexec to be usable from a HVM or PVH privileged domain. The first patch is a simple clean-up. The second patch allows hypercall structures to be ABI compatible between 32- and 64-bit guests (by reusing stuff present for domctls and sysctls). This seems better than having to keep adding compat handling for new hypercalls etc. Patch 3 introduces the new ABI. Patch 4 and 5 nearly completely reimplement the kexec load, unload and exec sub-ops. The old load_v1 sub-op is then implemented on top of the new code. Patch 6 calls the kexec image when dom0 crashes. This avoids having to alter dom0 kernels to do a exec sub-op call on crash -- an existing SHUTDOWN_crash. Patches 7 and 8 add the libxc API for the kexec calls. The required patch series for kexec-tools will be posted shortly. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-02-21 17:48 [PATCH 0/8] kexec: extended kexec hypercall for use with pv-ops kernels David Vrabel @ 2013-02-21 17:48 ` David Vrabel 2013-02-21 22:41 ` Daniel Kiper ` (2 more replies) 0 siblings, 3 replies; 34+ messages in thread From: David Vrabel @ 2013-02-21 17:48 UTC (permalink / raw) To: xen-devel; +Cc: Daniel Kiper, kexec, David Vrabel From: David Vrabel <david.vrabel@citrix.com> In the existing kexec hypercall, the load and unload ops depend on internals of the Linux kernel (the page list and code page provided by the kernel). The code page is used to transition between Xen context and the image so using kernel code doesn't make sense and will not work for PVH guests. Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops that no longer require a code page to be provided by the guest -- Xen now provides the code for calling the image directly. The new load op looks similar to the Linux kexec_load system call and allows the guest to provide the image data to be loaded. The guest specifies the architecture of the image which may be a 32-bit subarch of the hypervisor's architecture (i.e., an EM_386 image on an EM_X86_64 hypervisor). The toolstack can now load images without kernel involvement. This is required for supporting kexec when using a dom0 with an upstream kernel. Crash images are copied directly into the crash region on load. Default images are copied into Xen heap pages and a list of source and destination machine addresses is created. This is list is used in kexec_reloc() to relocate the image to its destination. The old load and unload sub-ops are still available (as KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top of the new infrastructure. Signed-off-by: David Vrabel <david.vrabel@citrix.com> --- xen/arch/x86/machine_kexec.c | 261 ++++++++++++++++++------- xen/arch/x86/x86_64/Makefile | 2 +- xen/arch/x86/x86_64/compat_kexec.S | 187 ----------------- xen/arch/x86/x86_64/kexec_reloc.S | 229 +++++++++++++++++++++ xen/common/kexec.c | 377 +++++++++++++++++++++++++++++------ xen/include/asm-x86/fixmap.h | 3 - xen/include/asm-x86/machine_kexec.h | 14 ++ xen/include/xen/kexec.h | 14 +- 8 files changed, 755 insertions(+), 332 deletions(-) delete mode 100644 xen/arch/x86/x86_64/compat_kexec.S create mode 100644 xen/arch/x86/x86_64/kexec_reloc.S create mode 100644 xen/include/asm-x86/machine_kexec.h diff --git a/xen/arch/x86/machine_kexec.c b/xen/arch/x86/machine_kexec.c index 8191ef1..0ec8c56 100644 --- a/xen/arch/x86/machine_kexec.c +++ b/xen/arch/x86/machine_kexec.c @@ -1,9 +1,18 @@ /****************************************************************************** * machine_kexec.c * + * Copyright (C) 2013 Citrix Systems R&D Ltd. + * + * Portions derived from Linux's arch/x86/kernel/machine_kexec_64.c. + * + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> + * * Xen port written by: * - Simon 'Horms' Horman <horms@verge.net.au> * - Magnus Damm <magnus@valinux.co.jp> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. */ #include <xen/types.h> @@ -11,63 +20,195 @@ #include <xen/guest_access.h> #include <asm/fixmap.h> #include <asm/hpet.h> +#include <asm/page.h> +#include <asm/machine_kexec.h> + +static void init_level2_page(l2_pgentry_t *l2, unsigned long addr) +{ + unsigned long end_addr; + + addr &= PAGE_MASK; + end_addr = addr + L2_PAGETABLE_ENTRIES * (1ul << L2_PAGETABLE_SHIFT); + + while ( addr < end_addr ) + { + l2e_write(l2++, l2e_from_paddr(addr, __PAGE_HYPERVISOR | _PAGE_PSE)); -typedef void (*relocate_new_kernel_t)( - unsigned long indirection_page, - unsigned long *page_list, - unsigned long start_address, - unsigned int preserve_context); + addr += 1ul << L2_PAGETABLE_SHIFT; + } +} -int machine_kexec_load(int type, int slot, xen_kexec_image_t *image) +static int init_level3_page(struct kexec_image *image, l3_pgentry_t *l3, + unsigned long addr, unsigned long last_addr) { - unsigned long prev_ma = 0; - int fix_base = FIX_KEXEC_BASE_0 + (slot * (KEXEC_XEN_NO_PAGES >> 1)); - int k; + unsigned long end_addr; - /* setup fixmap to point to our pages and record the virtual address - * in every odd index in page_list[]. - */ + addr &= PAGE_MASK; + end_addr = addr + L3_PAGETABLE_ENTRIES * (1ul << L3_PAGETABLE_SHIFT); + + while( (addr < last_addr) && (addr < end_addr) ) + { + struct page_info *l2_page; + l2_pgentry_t *l2; + + l2_page = kimage_alloc_control_page(image); + if ( !l2_page ) + return -ENOMEM; + l2 = page_to_virt(l2_page); + + init_level2_page(l2, addr); + l3e_write(l3++, l3e_from_page(l2_page, __PAGE_HYPERVISOR)); + + addr += 1ul << L3_PAGETABLE_SHIFT; + } + + return 0; +} + +/* + * Build a complete page table to identity map [addr, last_addr). + * + * Control pages are used so they do not overlap with the image source + * or destination. + */ +static int init_level4_page(struct kexec_image *image, l4_pgentry_t *l4, + unsigned long addr, unsigned long last_addr) +{ + unsigned long end_addr; + int result; + + addr &= PAGE_MASK; + end_addr = addr + L4_PAGETABLE_ENTRIES * (1ul << L4_PAGETABLE_SHIFT); + + while ( (addr < last_addr) && (addr < end_addr) ) + { + struct page_info *l3_page; + l3_pgentry_t *l3; + + l3_page = kimage_alloc_control_page(image); + if ( !l3_page ) + return -ENOMEM; + l3 = page_to_virt(l3_page); + + result = init_level3_page(image, l3, addr, last_addr); + if (result) + return result; + l4e_write(l4++, l4e_from_page(l3_page, __PAGE_HYPERVISOR)); + + addr += 1ul << L4_PAGETABLE_SHIFT; + } + + return 0; +} - for ( k = 0; k < KEXEC_XEN_NO_PAGES; k++ ) +/* + * Add a mapping for the control code page to the same virtual address + * as kexec_reloc. This allows us to keep running after these page + * tables are loaded in kexec_reloc. + * + * We don't really need to allocate control pages here as these + * entries won't be used while the kexec image is being copied, but it + * makes clean-up easier. + */ +static int init_transition_pgtable(struct kexec_image *image, l4_pgentry_t *l4) +{ + struct page_info *l3_page; + struct page_info *l2_page; + struct page_info *l1_page; + unsigned long vaddr, paddr; + l3_pgentry_t *l3; + l2_pgentry_t *l2; + l1_pgentry_t *l1; + + vaddr = (unsigned long)kexec_reloc; + paddr = page_to_maddr(image->control_code_page); + + l4 += l4_table_offset(vaddr); + if ( !(l4e_get_flags(*l4) & _PAGE_PRESENT) ) + { + l3_page = kimage_alloc_control_page(image); + if ( !l3_page ) + return -ENOMEM; + l4e_write(l4, l4e_from_page(l3_page, __PAGE_HYPERVISOR)); + } + + l3 = l4e_to_l3e(*l4) + l3_table_offset(vaddr); + if ( !(l3e_get_flags(*l3) & _PAGE_PRESENT) ) + { + l2_page = kimage_alloc_control_page(image); + if ( !l2_page ) + return -ENOMEM; + l3e_write(l3, l3e_from_page(l2_page, __PAGE_HYPERVISOR)); + } + + l2 = l3e_to_l2e(*l3) + l2_table_offset(vaddr); + if ( !(l2e_get_flags(*l2) & _PAGE_PRESENT) ) + { + l1_page = kimage_alloc_control_page(image); + if ( !l1_page ) + return -ENOMEM; + l2e_write(l2, l2e_from_page(l1_page, __PAGE_HYPERVISOR)); + } + + l1 = l2e_to_l1e(*l2) + l1_table_offset(vaddr); + l1e_write(l1, l1e_from_pfn(paddr >> PAGE_SHIFT, __PAGE_HYPERVISOR)); + return 0; +} + + +static int build_reloc_page_table(struct kexec_image *image) +{ + struct page_info *l4_page; + l4_pgentry_t *l4; + int result; + + l4_page = kimage_alloc_control_page(image); + if ( !l4_page ) + return -ENOMEM; + + l4 = page_to_virt(l4_page); + result = init_level4_page(image, l4, 0, max_page << PAGE_SHIFT); + if ( result ) + return result; + + result = init_transition_pgtable(image, l4); + if ( result ) + return result; + + image->aux_page = l4_page; + return 0; +} + +int machine_kexec_load(struct kexec_image *image) +{ + void *code_page; + int ret; + + switch ( image->arch ) { - if ( (k & 1) == 0 ) - { - /* Even pages: machine address. */ - prev_ma = image->page_list[k]; - } - else - { - /* Odd pages: va for previous ma. */ - if ( is_pv_32on64_domain(dom0) ) - { - /* - * The compatability bounce code sets up a page table - * with a 1-1 mapping of the first 1G of memory so - * VA==PA here. - * - * This Linux purgatory code still sets up separate - * high and low mappings on the control page (entries - * 0 and 1) but it is harmless if they are equal since - * that PT is not live at the time. - */ - image->page_list[k] = prev_ma; - } - else - { - set_fixmap(fix_base + (k >> 1), prev_ma); - image->page_list[k] = fix_to_virt(fix_base + (k >> 1)); - } - } + case EM_386: + case EM_X86_64: + break; + default: + return -EINVAL; } + code_page = page_to_virt(image->control_code_page); + memcpy(code_page, kexec_reloc, PAGE_SIZE); + + ret = build_reloc_page_table(image); + if ( ret < 0 ) + return ret; + return 0; } -void machine_kexec_unload(int type, int slot, xen_kexec_image_t *image) +void machine_kexec_unload(struct kexec_image *image) { + /* no-op. kimage_free() frees all control pages. */ } -void machine_reboot_kexec(xen_kexec_image_t *image) +void machine_reboot_kexec(struct kexec_image *image) { BUG_ON(smp_processor_id() != 0); smp_send_stop(); @@ -75,13 +216,10 @@ void machine_reboot_kexec(xen_kexec_image_t *image) BUG(); } -void machine_kexec(xen_kexec_image_t *image) +void machine_kexec(struct kexec_image *image) { - struct desc_ptr gdt_desc = { - .base = (unsigned long)(boot_cpu_gdt_table - FIRST_RESERVED_GDT_ENTRY), - .limit = LAST_RESERVED_GDT_BYTE - }; int i; + unsigned long reloc_flags = 0; /* We are about to permenantly jump out of the Xen context into the kexec * purgatory code. We really dont want to be still servicing interupts. @@ -109,29 +247,12 @@ void machine_kexec(xen_kexec_image_t *image) * not like running with NMIs disabled. */ enable_nmis(); - /* - * compat_machine_kexec() returns to idle pagetables, which requires us - * to be running on a static GDT mapping (idle pagetables have no GDT - * mappings in their per-domain mapping area). - */ - asm volatile ( "lgdt %0" : : "m" (gdt_desc) ); + if ( image->arch == EM_386 ) + reloc_flags |= KEXEC_RELOC_FLAG_COMPAT; - if ( is_pv_32on64_domain(dom0) ) - { - compat_machine_kexec(image->page_list[1], - image->indirection_page, - image->page_list, - image->start_address); - } - else - { - relocate_new_kernel_t rnk; - - rnk = (relocate_new_kernel_t) image->page_list[1]; - (*rnk)(image->indirection_page, image->page_list, - image->start_address, - 0 /* preserve_context */); - } + kexec_reloc(page_to_maddr(image->control_code_page), + page_to_maddr(image->aux_page), + image->head, image->entry_maddr, reloc_flags); } int machine_kexec_get(xen_kexec_range_t *range) diff --git a/xen/arch/x86/x86_64/Makefile b/xen/arch/x86/x86_64/Makefile index d56e12d..7f8fb3d 100644 --- a/xen/arch/x86/x86_64/Makefile +++ b/xen/arch/x86/x86_64/Makefile @@ -11,11 +11,11 @@ obj-y += mmconf-fam10h.o obj-y += mmconfig_64.o obj-y += mmconfig-shared.o obj-y += compat.o -obj-bin-y += compat_kexec.o obj-y += domain.o obj-y += physdev.o obj-y += platform_hypercall.o obj-y += cpu_idle.o obj-y += cpufreq.o +obj-bin-y += kexec_reloc.o obj-$(crash_debug) += gdbstub.o diff --git a/xen/arch/x86/x86_64/compat_kexec.S b/xen/arch/x86/x86_64/compat_kexec.S deleted file mode 100644 index fc92af9..0000000 --- a/xen/arch/x86/x86_64/compat_kexec.S +++ /dev/null @@ -1,187 +0,0 @@ -/* - * Compatibility kexec handler. - */ - -/* - * NOTE: We rely on Xen not relocating itself above the 4G boundary. This is - * currently true but if it ever changes then compat_pg_table will - * need to be moved back below 4G at run time. - */ - -#include <xen/config.h> - -#include <asm/asm_defns.h> -#include <asm/msr.h> -#include <asm/page.h> - -/* The unrelocated physical address of a symbol. */ -#define SYM_PHYS(sym) ((sym) - __XEN_VIRT_START) - -/* Load physical address of symbol into register and relocate it. */ -#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ - add xen_phys_start(%rip), reg - -/* - * Relocate a physical address in memory. Size of temporary register - * determines size of the value to relocate. - */ -#define RELOCATE_MEM(addr,reg) mov addr(%rip), reg ; \ - add xen_phys_start(%rip), reg ; \ - mov reg, addr(%rip) - - .text - - .code64 - -ENTRY(compat_machine_kexec) - /* x86/64 x86/32 */ - /* %rdi - relocate_new_kernel_t CALL */ - /* %rsi - indirection page 4(%esp) */ - /* %rdx - page_list 8(%esp) */ - /* %rcx - start address 12(%esp) */ - /* cpu has pae 16(%esp) */ - - /* Shim the 64 bit page_list into a 32 bit page_list. */ - mov $12,%r9 - lea compat_page_list(%rip), %rbx -1: dec %r9 - movl (%rdx,%r9,8),%eax - movl %eax,(%rbx,%r9,4) - test %r9,%r9 - jnz 1b - - RELOCATE_SYM(compat_page_list,%rdx) - - /* Relocate compatibility mode entry point address. */ - RELOCATE_MEM(compatibility_mode_far,%eax) - - /* Relocate compat_pg_table. */ - RELOCATE_MEM(compat_pg_table, %rax) - RELOCATE_MEM(compat_pg_table+0x8, %rax) - RELOCATE_MEM(compat_pg_table+0x10,%rax) - RELOCATE_MEM(compat_pg_table+0x18,%rax) - - /* - * Setup an identity mapped region in PML4[0] of idle page - * table. - */ - RELOCATE_SYM(l3_identmap,%rax) - or $0x63,%rax - mov %rax, idle_pg_table(%rip) - - /* Switch to idle page table. */ - RELOCATE_SYM(idle_pg_table,%rax) - movq %rax, %cr3 - - /* Switch to identity mapped compatibility stack. */ - RELOCATE_SYM(compat_stack,%rax) - movq %rax, %rsp - - /* Save xen_phys_start for 32 bit code. */ - movq xen_phys_start(%rip), %rbx - - /* Jump to low identity mapping in compatibility mode. */ - ljmp *compatibility_mode_far(%rip) - ud2 - -compatibility_mode_far: - .long SYM_PHYS(compatibility_mode) - .long __HYPERVISOR_CS32 - - /* - * We use 5 words of stack for the arguments passed to the kernel. The - * kernel only uses 1 word before switching to its own stack. Allocate - * 16 words to give "plenty" of room. - */ - .fill 16,4,0 -compat_stack: - - .code32 - -#undef RELOCATE_SYM -#undef RELOCATE_MEM - -/* - * Load physical address of symbol into register and relocate it. %rbx - * contains xen_phys_start(%rip) saved before jump to compatibility - * mode. - */ -#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ - add %ebx, reg - -compatibility_mode: - /* Setup some sane segments. */ - movl $__HYPERVISOR_DS32, %eax - movl %eax, %ds - movl %eax, %es - movl %eax, %fs - movl %eax, %gs - movl %eax, %ss - - /* Push arguments onto stack. */ - pushl $0 /* 20(%esp) - preserve context */ - pushl $1 /* 16(%esp) - cpu has pae */ - pushl %ecx /* 12(%esp) - start address */ - pushl %edx /* 8(%esp) - page list */ - pushl %esi /* 4(%esp) - indirection page */ - pushl %edi /* 0(%esp) - CALL */ - - /* Disable paging and therefore leave 64 bit mode. */ - movl %cr0, %eax - andl $~X86_CR0_PG, %eax - movl %eax, %cr0 - - /* Switch to 32 bit page table. */ - RELOCATE_SYM(compat_pg_table, %eax) - movl %eax, %cr3 - - /* Clear MSR_EFER[LME], disabling long mode */ - movl $MSR_EFER,%ecx - rdmsr - btcl $_EFER_LME,%eax - wrmsr - - /* Re-enable paging, but only 32 bit mode now. */ - movl %cr0, %eax - orl $X86_CR0_PG, %eax - movl %eax, %cr0 - jmp 1f -1: - - popl %eax - call *%eax - ud2 - - .data - .align 4 -compat_page_list: - .fill 12,4,0 - - .align 32,0 - - /* - * These compat page tables contain an identity mapping of the - * first 4G of the physical address space. - */ -compat_pg_table: - .long SYM_PHYS(compat_pg_table_l2) + 0*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 1*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 2*PAGE_SIZE + 0x01, 0 - .long SYM_PHYS(compat_pg_table_l2) + 3*PAGE_SIZE + 0x01, 0 - - .section .data.page_aligned, "aw", @progbits - .align PAGE_SIZE,0 -compat_pg_table_l2: - .macro identmap from=0, count=512 - .if \count-1 - identmap "(\from+0)","(\count/2)" - identmap "(\from+(0x200000*(\count/2)))","(\count/2)" - .else - .quad 0x00000000000000e3 + \from - .endif - .endm - - identmap 0x00000000 - identmap 0x40000000 - identmap 0x80000000 - identmap 0xc0000000 diff --git a/xen/arch/x86/x86_64/kexec_reloc.S b/xen/arch/x86/x86_64/kexec_reloc.S new file mode 100644 index 0000000..e68842c --- /dev/null +++ b/xen/arch/x86/x86_64/kexec_reloc.S @@ -0,0 +1,229 @@ +/* + * Relocate a kexec_image to its destination and call it. + * + * Copyright (C) 2013 Citrix Systems R&D Ltd. + * + * Portions derived from Linux's arch/x86/kernel/relocate_kernel_64.S. + * + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ +#include <xen/config.h> + +#include <asm/asm_defns.h> +#include <asm/msr.h> +#include <asm/page.h> +#include <asm/machine_kexec.h> + +/* The unrelocated physical address of a symbol. */ +#define SYM_PHYS(sym) ((sym) - __XEN_VIRT_START) + +/* Load physical address of symbol into register and relocate it. */ +#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ + add xen_phys_start(%rip), reg + +#define DBG(c) \ +1: mov $0x3f8+5, %dx ; \ + inb %dx, %al ; \ + test $0x20, %al ; \ + je 1b ; \ + mov $0x3f8, %dx ; \ + mov $c, %al ; \ + outb %al, %dx ; + + .text + .align PAGE_SIZE + .code64 + +ENTRY(kexec_reloc) + /* %rdi - code_page maddr */ + /* %rsi - page table maddr */ + /* %rdx - indirection page maddr */ + /* %rcx - entry maddr */ + /* %r8 - flags */ + + mov %rdx, %rbx + + DBG('A') + + /* Setup stack. */ + RELOCATE_SYM(reloc_stack, %rax) + mov %rax, %rsp + + DBG('B') + + wbinvd + movq %cr4, %rax + andq $~(X86_CR4_PGE|X86_CR4_PCE|X86_CR4_MCE), %rax + movq %rax, %cr4 + + /* Load reloc page table. */ + movq %rsi, %cr3 + + DBG('C') + + /* Jump to identity mapped code. */ + movq %rdi, %r9 + addq $(identity_mapped - kexec_reloc), %r9 + + DBG('D') + + jmp *%r9 + +identity_mapped: + DBG('E') + + pushq %rcx + pushq %rbx + pushq %rsi + pushq %rdi + + movq %rbx, %rdi + call swap_pages + + popq %rdi + popq %rsi + popq %rbx + popq %rcx + + DBG('F') + + /* Need to switch to 32-bit mode? */ + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 + jnz call_32_bit + +call_64_bit: + DBG('6') + + /* Call the image entry point. This should never return. */ + call *%rcx + ud2 + +call_32_bit: + DBG('3') + + /* Relocate compatibility mode entry point address. */ + movl %edi, %eax + addl $(compatibility_mode - kexec_reloc), %eax + movl %eax, compatibility_mode_far(%rip) + + DBG('I') + + /* Load compat GDT. */ + movq %rdi, %rax + addq $(compat_mode_gdt - kexec_reloc), %rax + movq %rax, (compat_mode_gdt_desc + 2)(%rip) + lgdt compat_mode_gdt_desc(%rip) + + DBG('J') + + /* Enter compatibility mode. */ + ljmp *compatibility_mode_far(%rip) + +swap_pages: + /* %rdi - indirection page maddr */ + movq %rdi, %rcx + xorq %rdi, %rdi + xorq %rsi, %rsi + jmp 1f + +0: /* top, read another word for the indirection page */ + + movq (%rbx), %rcx + addq $8, %rbx +1: + testq $0x1, %rcx /* is it a destination page? */ + jz 2f + movq %rcx, %rdi + andq $0xfffffffffffff000, %rdi + jmp 0b +2: + testq $0x2, %rcx /* is it an indirection page? */ + jz 2f + movq %rcx, %rbx + andq $0xfffffffffffff000, %rbx + jmp 0b +2: + testq $0x4, %rcx /* is it the done indicator? */ + jz 2f + jmp 3f +2: + testq $0x8, %rcx /* is it the source indicator? */ + jz 0b /* Ignore it otherwise */ + movq %rcx, %rsi /* For ever source page do a copy */ + andq $0xfffffffffffff000, %rsi + + movq %rdi, %rdx + movq %rsi, %rax + + movq %r10, %rdi + movq $512, %rcx + rep movsq + + movq %rax, %rdi + movq %rdx, %rsi + movq $512, %rcx + rep movsq + + movq %rdx, %rdi + movq %r10, %rsi + movq $512, %rcx + rep movsq + + lea PAGE_SIZE(%rax), %rsi + jmp 0b +3: + ret + + .code32 + +compatibility_mode: + DBG('K') + + /* Setup some sane segments. */ + movl $0x0008, %eax + movl %eax, %ds + movl %eax, %es + movl %eax, %fs + movl %eax, %gs + movl %eax, %ss + + DBG('L') + + /* Disable paging and therefore leave 64 bit mode. */ + movl %cr0, %eax + andl $~X86_CR0_PG, %eax + movl %eax, %cr0 + + DBG('M') + + /* Call the image entry point. This should never return. */ + call *%ecx + ud2 + + .align 16 +compatibility_mode_far: + .long SYM_PHYS(compatibility_mode) + .word 0x0010 + + .align 16 +compat_mode_gdt_desc: + .word (3*8)-1 + .quad SYM_PHYS(compat_mode_gdt) + + .align 16 +compat_mode_gdt: + .quad 0x0000000000000000 /* null */ + .quad 0x00cf92000000ffff /* 0x0008 ring 0 data */ + .quad 0x00cf9a000000ffff /* 0x0010 ring 0 code, compatibility */ + + /* + * 16 words of stack are more than enough. + */ + .fill 16,8,0 +reloc_stack: + + .globl kexec_reloc_size + .set kexec_reloc_size, . - kexec_reloc diff --git a/xen/common/kexec.c b/xen/common/kexec.c index 2cbb62c..2926274 100644 --- a/xen/common/kexec.c +++ b/xen/common/kexec.c @@ -23,6 +23,7 @@ #include <xen/version.h> #include <xen/console.h> #include <xen/kexec.h> +#include <xen/kimage.h> #include <public/elfnote.h> #include <xsm/xsm.h> #include <xen/cpu.h> @@ -45,7 +46,7 @@ static Elf_Note *xen_crash_note; static cpumask_t crash_saved_cpus; -static xen_kexec_image_t kexec_image[KEXEC_IMAGE_NR]; +static struct kexec_image *kexec_image[KEXEC_IMAGE_NR]; #define KEXEC_FLAG_DEFAULT_POS (KEXEC_IMAGE_NR + 0) #define KEXEC_FLAG_CRASH_POS (KEXEC_IMAGE_NR + 1) @@ -309,14 +310,14 @@ void kexec_crash(void) kexec_common_shutdown(); kexec_crash_save_cpu(); machine_crash_shutdown(); - machine_kexec(&kexec_image[KEXEC_IMAGE_CRASH_BASE + pos]); + machine_kexec(kexec_image[KEXEC_IMAGE_CRASH_BASE + pos]); BUG(); } static long kexec_reboot(void *_image) { - xen_kexec_image_t *image = _image; + struct kexec_image *image = _image; kexecing = TRUE; @@ -732,63 +733,245 @@ static void crash_save_vmcoreinfo(void) #endif } -static int kexec_load_unload_internal(unsigned long op, xen_kexec_load_v1_t *load) +static void kexec_unload_image(struct kexec_image *image) +{ + if ( !image ) + return; + + machine_kexec_unload(image); +} + +static int kexec_exec(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_exec_t exec; + struct kexec_image *image; + int base, bit, pos, ret = -EINVAL; + + if ( unlikely(copy_from_guest(&exec, uarg, 1)) ) + return -EFAULT; + + if ( kexec_load_get_bits(exec.type, &base, &bit) ) + return -EINVAL; + + pos = (test_bit(bit, &kexec_flags) != 0); + + /* Only allow kexec/kdump into loaded images */ + if ( !test_bit(base + pos, &kexec_flags) ) + return -ENOENT; + + switch (exec.type) + { + case KEXEC_TYPE_DEFAULT: + image = kexec_image[base + pos]; + ret = continue_hypercall_on_cpu(0, kexec_reboot, image); + break; + case KEXEC_TYPE_CRASH: + kexec_crash(); /* Does not return */ + break; + } + + return -EINVAL; /* never reached */ +} + +static int kexec_swap_images(int type, struct kexec_image *new, + struct kexec_image **old) { - xen_kexec_image_t *image; int base, bit, pos; - int ret = 0; + int new_slot, old_slot; + + *old = NULL; + + spin_lock(&kexec_lock); + + if ( test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags) ) + { + spin_unlock(&kexec_lock); + return -EBUSY; + } - if ( kexec_load_get_bits(load->type, &base, &bit) ) + if ( kexec_load_get_bits(type, &base, &bit) ) return -EINVAL; pos = (test_bit(bit, &kexec_flags) != 0); + old_slot = base + pos; + new_slot = base + !pos; - /* Load the user data into an unused image */ - if ( op == KEXEC_CMD_kexec_load ) + if ( new ) { - image = &kexec_image[base + !pos]; + kexec_image[new_slot] = new; + set_bit(new_slot, &kexec_flags); + } + change_bit(bit, &kexec_flags); - BUG_ON(test_bit((base + !pos), &kexec_flags)); /* must be free */ + clear_bit(old_slot, &kexec_flags); + *old = kexec_image[old_slot]; - memcpy(image, &load->image, sizeof(*image)); + spin_unlock(&kexec_lock); - if ( !(ret = machine_kexec_load(load->type, base + !pos, image)) ) - { - /* Set image present bit */ - set_bit((base + !pos), &kexec_flags); + return 0; +} - /* Make new image the active one */ - change_bit(bit, &kexec_flags); - } +static int kexec_load_slot(struct kexec_image *kimage) +{ + struct kexec_image *old_kimage; + int ret = -ENOMEM; + + ret = machine_kexec_load(kimage); + if ( ret < 0 ) + goto error; + + crash_save_vmcoreinfo(); - crash_save_vmcoreinfo(); + ret = kexec_swap_images(kimage->type, kimage, &old_kimage); + if ( ret < 0 ) + goto error; + + kexec_unload_image(old_kimage); + + return 0; + +error: + kimage_free(kimage); + return ret; +} + +static uint16_t kexec_load_v1_arch(void) +{ +#ifdef CONFIG_X86 + return is_pv_32on64_domain(dom0) ? EM_386 : EM_X86_64; +#else + return EM_NONE; +#endif +} + +static int kexec_segments_add_page(unsigned *nr_segments, + xen_kexec_segment_t *segments, + unsigned long mfn) +{ + unsigned long maddr = mfn << PAGE_SHIFT; + int n = *nr_segments; + + /* Need a new segment? */ + if ( n == 0 + || segments[n-1].dest_maddr + segments[n-1].dest_size != maddr ) + { + n++; + if ( n == KEXEC_SEGMENT_MAX ) + return -EINVAL; + *nr_segments = n; + + set_xen_guest_handle(segments[n-1].buf, NULL); + segments[n-1].buf_size = 0; + segments[n-1].dest_maddr = maddr; + segments[n-1].dest_size = 0; } - /* Unload the old image if present and load successful */ - if ( ret == 0 && !test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags) ) + segments[n-1].dest_size += PAGE_SIZE; + + return 0; +} + +static int kexec_segments_from_ind_page(unsigned long mfn, + unsigned *nr_segments, + xen_kexec_segment_t *segments) +{ + void *page; + unsigned long *entry; + int ret; + + page = vmap(&mfn, 1); + if ( page == NULL ) + return -ENOMEM; + + /* + * Walk the indirection page list, adding destination pages to the + * segments. + */ + for ( entry = page; ; entry++ ) { - if ( test_and_clear_bit((base + pos), &kexec_flags) ) + unsigned long ind; + + ind = (*entry) & 0xf; + mfn = (*entry) >> PAGE_SHIFT; + + switch ( ind ) { - image = &kexec_image[base + pos]; - machine_kexec_unload(load->type, base + pos, image); + case IND_DESTINATION: + ret = kexec_segments_add_page(nr_segments, segments, mfn); + if ( ret < 0 ) + return ret; + break; + case IND_INDIRECTION: + vunmap(page); + page = vmap(&mfn, 1); + if ( page == NULL ) + return -ENOMEM; + entry = page; + break; + case IND_DONE: + goto done; + case IND_SOURCE: + break; } } +done: + return 0; +} + +static int kexec_do_load_v1(xen_kexec_load_v1_t *load) +{ + struct kexec_image *kimage = NULL; + xen_kexec_segment_t *segments; + uint16_t arch; + unsigned nr_segments = 0; + int ret; + + arch = kexec_load_v1_arch(); + if ( arch == EM_NONE ) + return -ENOSYS; + + segments = xmalloc_array(xen_kexec_segment_t, KEXEC_SEGMENT_MAX); + if ( segments == NULL ) + return -ENOMEM; + + ret = kexec_segments_from_ind_page(load->image.indirection_page >> PAGE_SHIFT, + &nr_segments, segments); + if ( ret < 0 ) + goto error; + + ret = kimage_alloc(&kimage, load->type, arch, load->image.start_address, + nr_segments, segments); + if ( ret < 0 ) + goto error; + + /* kexec_reloc() uses the same format for the indirection pages so + reuse the provided ones. */ + kimage->head = load->image.indirection_page; + + ret = kexec_load_slot(kimage); + if ( ret < 0 ) + goto error; + + return 0; +error: + if ( !kimage ) + xfree(segments); + kimage_free(kimage); return ret; } -static int kexec_load_unload(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load_v1(XEN_GUEST_HANDLE_PARAM(void) uarg) { xen_kexec_load_v1_t load; if ( unlikely(copy_from_guest(&load, uarg, 1)) ) return -EFAULT; - return kexec_load_unload_internal(op, &load); + return kexec_do_load_v1(&load); } -static int kexec_load_unload_compat(unsigned long op, - XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) { #ifdef CONFIG_COMPAT compat_kexec_load_v1_t compat_load; @@ -807,49 +990,113 @@ static int kexec_load_unload_compat(unsigned long op, load.type = compat_load.type; XLAT_kexec_image(&load.image, &compat_load.image); - return kexec_load_unload_internal(op, &load); -#else /* CONFIG_COMPAT */ + return kexec_do_load_v1(&load); +#else return 0; -#endif /* CONFIG_COMPAT */ +#endif } -static int kexec_exec(XEN_GUEST_HANDLE_PARAM(void) uarg) +static int kexec_load(XEN_GUEST_HANDLE_PARAM(void) uarg) { - xen_kexec_exec_t exec; - xen_kexec_image_t *image; - int base, bit, pos, ret = -EINVAL; + xen_kexec_load_t load; + xen_kexec_segment_t *segments; + struct kexec_image *kimage = NULL; + int ret; - if ( unlikely(copy_from_guest(&exec, uarg, 1)) ) + if ( copy_from_guest(&load, uarg, 1) ) return -EFAULT; - if ( kexec_load_get_bits(exec.type, &base, &bit) ) + if ( load.nr_segments >= KEXEC_SEGMENT_MAX ) return -EINVAL; - pos = (test_bit(bit, &kexec_flags) != 0); - - /* Only allow kexec/kdump into loaded images */ - if ( !test_bit(base + pos, &kexec_flags) ) - return -ENOENT; + segments = xmalloc_array(xen_kexec_segment_t, load.nr_segments); + if ( segments == NULL ) + return -ENOMEM; - switch (exec.type) + if ( copy_from_guest(segments, load.segments, load.nr_segments) ) { - case KEXEC_TYPE_DEFAULT: - image = &kexec_image[base + pos]; - ret = continue_hypercall_on_cpu(0, kexec_reboot, image); - break; - case KEXEC_TYPE_CRASH: - kexec_crash(); /* Does not return */ - break; + ret = -EFAULT; + goto error; } - return -EINVAL; /* never reached */ + ret = kimage_alloc(&kimage, load.type, load.arch, load.entry_maddr, + load.nr_segments, segments); + if ( ret < 0 ) + goto error; + + ret = kimage_load_segments(kimage); + if ( ret < 0 ) + goto error; + + ret = kexec_load_slot(kimage); + if ( ret < 0 ) + goto error; + + return 0; + +error: + if ( ! kimage ) + xfree(segments); + kimage_free(kimage); + return ret; +} + +static int kexec_do_unload(xen_kexec_unload_t *unload) +{ + struct kexec_image *old_kimage; + int ret; + + ret = kexec_swap_images(unload->type, NULL, &old_kimage); + if ( ret < 0 ) + return ret; + + kexec_unload_image(old_kimage); + + return 0; +} + +static int kexec_unload_v1(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_load_v1_t load; + xen_kexec_unload_t unload; + + if ( copy_from_guest(&load, uarg, 1) ) + return -EFAULT; + + unload.type = load.type; + return kexec_do_unload(&unload); +} + +static int kexec_unload_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ +#ifdef CONFIG_COMPAT + compat_kexec_load_v1_t compat_load; + xen_kexec_unload_t unload; + + if ( copy_from_guest(&compat_load, uarg, 1) ) + return -EFAULT; + + unload.type = compat_load.type; + return kexec_do_unload(&unload); +#else + return 0; +#endif +} + +static int kexec_unload(XEN_GUEST_HANDLE_PARAM(void) uarg) +{ + xen_kexec_unload_t unload; + + if ( unlikely(copy_from_guest(&unload, uarg, 1)) ) + return -EFAULT; + + return kexec_do_unload(&unload); } static int do_kexec_op_internal(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) uarg, bool_t compat) { - unsigned long flags; int ret = -EINVAL; ret = xsm_kexec(XSM_PRIV); @@ -865,20 +1112,26 @@ static int do_kexec_op_internal(unsigned long op, ret = kexec_get_range(uarg); break; case KEXEC_CMD_kexec_load_v1: + if ( compat ) + ret = kexec_load_v1_compat(uarg); + else + ret = kexec_load_v1(uarg); + break; case KEXEC_CMD_kexec_unload_v1: - spin_lock_irqsave(&kexec_lock, flags); - if (!test_bit(KEXEC_FLAG_IN_PROGRESS, &kexec_flags)) - { - if (compat) - ret = kexec_load_unload_compat(op, uarg); - else - ret = kexec_load_unload(op, uarg); - } - spin_unlock_irqrestore(&kexec_lock, flags); + if ( compat ) + ret = kexec_unload_v1_compat(uarg); + else + ret = kexec_unload_v1(uarg); break; case KEXEC_CMD_kexec: ret = kexec_exec(uarg); break; + case KEXEC_CMD_kexec_load: + ret = kexec_load(uarg); + break; + case KEXEC_CMD_kexec_unload: + ret = kexec_unload(uarg); + break; } return ret; diff --git a/xen/include/asm-x86/fixmap.h b/xen/include/asm-x86/fixmap.h index 2eefcf4..1695228 100644 --- a/xen/include/asm-x86/fixmap.h +++ b/xen/include/asm-x86/fixmap.h @@ -57,9 +57,6 @@ enum fixed_addresses { FIX_ACPI_END = FIX_ACPI_BEGIN + FIX_ACPI_PAGES - 1, FIX_HPET_BASE, FIX_CYCLONE_TIMER, - FIX_KEXEC_BASE_0, - FIX_KEXEC_BASE_END = FIX_KEXEC_BASE_0 \ - + ((KEXEC_XEN_NO_PAGES >> 1) * KEXEC_IMAGE_NR) - 1, FIX_IOMMU_REGS_BASE_0, FIX_IOMMU_REGS_END = FIX_IOMMU_REGS_BASE_0 + MAX_IOMMUS-1, FIX_IOMMU_MMIO_BASE_0, diff --git a/xen/include/asm-x86/machine_kexec.h b/xen/include/asm-x86/machine_kexec.h new file mode 100644 index 0000000..ec41099 --- /dev/null +++ b/xen/include/asm-x86/machine_kexec.h @@ -0,0 +1,14 @@ +#ifndef __X86_MACHINE_KEXEC_H__ +#define __X86_MACHINE_KEXEC_H__ + +#define KEXEC_RELOC_FLAG_COMPAT 0x1 /* 32-bit image */ + +#ifndef __ASSEMBLY__ + +extern void kexec_reloc(unsigned long reloc_code, unsigned long reloc_pt, + unsigned long ind_maddr, unsigned long entry_maddr, + unsigned long flags); + +#endif + +#endif /* __X86_MACHINE_KEXEC_H__ */ diff --git a/xen/include/xen/kexec.h b/xen/include/xen/kexec.h index b3ca8b0..b1177d8 100644 --- a/xen/include/xen/kexec.h +++ b/xen/include/xen/kexec.h @@ -6,6 +6,7 @@ #include <public/kexec.h> #include <asm/percpu.h> #include <xen/elfcore.h> +#include <xen/kimage.h> typedef struct xen_kexec_reserve { unsigned long size; @@ -40,11 +41,11 @@ extern enum low_crashinfo low_crashinfo_mode; extern paddr_t crashinfo_maxaddr_bits; void kexec_early_calculations(void); -int machine_kexec_load(int type, int slot, xen_kexec_image_t *image); -void machine_kexec_unload(int type, int slot, xen_kexec_image_t *image); +int machine_kexec_load(struct kexec_image *image); +void machine_kexec_unload(struct kexec_image *image); void machine_kexec_reserved(xen_kexec_reserve_t *reservation); -void machine_reboot_kexec(xen_kexec_image_t *image); -void machine_kexec(xen_kexec_image_t *image); +void machine_reboot_kexec(struct kexec_image *image); +void machine_kexec(struct kexec_image *image); void kexec_crash(void); void kexec_crash_save_cpu(void); crash_xen_info_t *kexec_crash_save_info(void); @@ -52,11 +53,6 @@ void machine_crash_shutdown(void); int machine_kexec_get(xen_kexec_range_t *range); int machine_kexec_get_xen(xen_kexec_range_t *range); -void compat_machine_kexec(unsigned long rnk, - unsigned long indirection_page, - unsigned long *page_list, - unsigned long start_address); - /* vmcoreinfo stuff */ #define VMCOREINFO_BYTES (4096) #define VMCOREINFO_NOTE_NAME "VMCOREINFO_XEN" -- 1.7.2.5 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply related [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-02-21 17:48 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel @ 2013-02-21 22:41 ` Daniel Kiper 2013-03-08 11:23 ` Daniel Kiper 2013-03-12 11:36 ` Daniel Kiper 2 siblings, 0 replies; 34+ messages in thread From: Daniel Kiper @ 2013-02-21 22:41 UTC (permalink / raw) To: David Vrabel; +Cc: kexec, xen-devel On Thu, Feb 21, 2013 at 05:48:11PM +0000, David Vrabel wrote: > From: David Vrabel <david.vrabel@citrix.com> > > In the existing kexec hypercall, the load and unload ops depend on > internals of the Linux kernel (the page list and code page provided by > the kernel). The code page is used to transition between Xen context > and the image so using kernel code doesn't make sense and will not > work for PVH guests. > > Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops > that no longer require a code page to be provided by the guest -- Xen > now provides the code for calling the image directly. > > The new load op looks similar to the Linux kexec_load system call and > allows the guest to provide the image data to be loaded. The guest > specifies the architecture of the image which may be a 32-bit subarch > of the hypervisor's architecture (i.e., an EM_386 image on an > EM_X86_64 hypervisor). > > The toolstack can now load images without kernel involvement. This is > required for supporting kexec when using a dom0 with an upstream > kernel. > > Crash images are copied directly into the crash region on load. > Default images are copied into Xen heap pages and a list of source and > destination machine addresses is created. This is list is used in > kexec_reloc() to relocate the image to its destination. > > The old load and unload sub-ops are still available (as > KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top > of the new infrastructure. > > Signed-off-by: David Vrabel <david.vrabel@citrix.com> [...] > diff --git a/xen/arch/x86/x86_64/kexec_reloc.S b/xen/arch/x86/x86_64/kexec_reloc.S > new file mode 100644 > index 0000000..e68842c > --- /dev/null > +++ b/xen/arch/x86/x86_64/kexec_reloc.S > @@ -0,0 +1,229 @@ > +/* > + * Relocate a kexec_image to its destination and call it. > + * > + * Copyright (C) 2013 Citrix Systems R&D Ltd. > + * > + * Portions derived from Linux's arch/x86/kernel/relocate_kernel_64.S. > + * > + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> > + * > + * This source code is licensed under the GNU General Public License, > + * Version 2. See the file COPYING for more details. > + */ > +#include <xen/config.h> > + > +#include <asm/asm_defns.h> > +#include <asm/msr.h> > +#include <asm/page.h> > +#include <asm/machine_kexec.h> > + > +/* The unrelocated physical address of a symbol. */ > +#define SYM_PHYS(sym) ((sym) - __XEN_VIRT_START) > + > +/* Load physical address of symbol into register and relocate it. */ > +#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ > + add xen_phys_start(%rip), reg > + > +#define DBG(c) \ > +1: mov $0x3f8+5, %dx ; \ > + inb %dx, %al ; \ > + test $0x20, %al ; \ > + je 1b ; \ > + mov $0x3f8, %dx ; \ > + mov $c, %al ; \ > + outb %al, %dx ; Nice feature but I think that it is dangerous to write to serial port unconditionally. There are a lot of machines in the wild which do not have coms these days. Maybe it should be enabled if Xen is compiled with debug feature. Then serial port address should be established on the base of console argument. Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-02-21 17:48 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel 2013-02-21 22:41 ` Daniel Kiper @ 2013-03-08 11:23 ` Daniel Kiper 2013-03-08 11:40 ` David Vrabel 2013-03-12 11:36 ` Daniel Kiper 2 siblings, 1 reply; 34+ messages in thread From: Daniel Kiper @ 2013-03-08 11:23 UTC (permalink / raw) To: David Vrabel; +Cc: kexec, xen-devel On Thu, Feb 21, 2013 at 05:48:11PM +0000, David Vrabel wrote: > From: David Vrabel <david.vrabel@citrix.com> > > In the existing kexec hypercall, the load and unload ops depend on > internals of the Linux kernel (the page list and code page provided by > the kernel). The code page is used to transition between Xen context > and the image so using kernel code doesn't make sense and will not > work for PVH guests. > > Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops > that no longer require a code page to be provided by the guest -- Xen > now provides the code for calling the image directly. > > The new load op looks similar to the Linux kexec_load system call and > allows the guest to provide the image data to be loaded. The guest > specifies the architecture of the image which may be a 32-bit subarch > of the hypervisor's architecture (i.e., an EM_386 image on an > EM_X86_64 hypervisor). > > The toolstack can now load images without kernel involvement. This is > required for supporting kexec when using a dom0 with an upstream > kernel. > > Crash images are copied directly into the crash region on load. > Default images are copied into Xen heap pages and a list of source and > destination machine addresses is created. This is list is used in > kexec_reloc() to relocate the image to its destination. > > The old load and unload sub-ops are still available (as > KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top > of the new infrastructure. > > Signed-off-by: David Vrabel <david.vrabel@citrix.com> [...] > diff --git a/xen/arch/x86/x86_64/kexec_reloc.S b/xen/arch/x86/x86_64/kexec_reloc.S > new file mode 100644 > index 0000000..e68842c > --- /dev/null > +++ b/xen/arch/x86/x86_64/kexec_reloc.S > @@ -0,0 +1,229 @@ > +/* > + * Relocate a kexec_image to its destination and call it. > + * > + * Copyright (C) 2013 Citrix Systems R&D Ltd. > + * > + * Portions derived from Linux's arch/x86/kernel/relocate_kernel_64.S. > + * > + * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> > + * > + * This source code is licensed under the GNU General Public License, > + * Version 2. See the file COPYING for more details. > + */ > +#include <xen/config.h> > + > +#include <asm/asm_defns.h> > +#include <asm/msr.h> > +#include <asm/page.h> > +#include <asm/machine_kexec.h> > + > +/* The unrelocated physical address of a symbol. */ > +#define SYM_PHYS(sym) ((sym) - __XEN_VIRT_START) > + > +/* Load physical address of symbol into register and relocate it. */ > +#define RELOCATE_SYM(sym,reg) mov $SYM_PHYS(sym), reg ; \ > + add xen_phys_start(%rip), reg > + > +#define DBG(c) \ > +1: mov $0x3f8+5, %dx ; \ > + inb %dx, %al ; \ > + test $0x20, %al ; \ > + je 1b ; \ > + mov $0x3f8, %dx ; \ > + mov $c, %al ; \ > + outb %al, %dx ; > + > + .text > + .align PAGE_SIZE > + .code64 > + > +ENTRY(kexec_reloc) > + /* %rdi - code_page maddr */ > + /* %rsi - page table maddr */ > + /* %rdx - indirection page maddr */ > + /* %rcx - entry maddr */ > + /* %r8 - flags */ > + > + mov %rdx, %rbx > + > + DBG('A') > + > + /* Setup stack. */ > + RELOCATE_SYM(reloc_stack, %rax) > + mov %rax, %rsp > + > + DBG('B') > + > + wbinvd > + movq %cr4, %rax > + andq $~(X86_CR4_PGE|X86_CR4_PCE|X86_CR4_MCE), %rax > + movq %rax, %cr4 > + > + /* Load reloc page table. */ > + movq %rsi, %cr3 > + > + DBG('C') > + > + /* Jump to identity mapped code. */ > + movq %rdi, %r9 > + addq $(identity_mapped - kexec_reloc), %r9 > + > + DBG('D') > + > + jmp *%r9 > + > +identity_mapped: > + DBG('E') > + > + pushq %rcx > + pushq %rbx > + pushq %rsi > + pushq %rdi > + > + movq %rbx, %rdi > + call swap_pages > + > + popq %rdi > + popq %rsi > + popq %rbx > + popq %rcx > + > + DBG('F') > + > + /* Need to switch to 32-bit mode? */ > + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 > + jnz call_32_bit Why do you need that? This is not needed because purgatory code from kexec-tools always switches to 32-bit mode. Please check kexec-tools/purgatory/arch/x86_64/entry64.S. Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-03-08 11:23 ` Daniel Kiper @ 2013-03-08 11:40 ` David Vrabel 2013-03-08 12:21 ` Daniel Kiper 0 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-03-08 11:40 UTC (permalink / raw) To: Daniel Kiper; +Cc: kexec@lists.infradead.org, xen-devel@lists.xen.org On 08/03/13 11:23, Daniel Kiper wrote: > On Thu, Feb 21, 2013 at 05:48:11PM +0000, David Vrabel wrote: >> >> + /* Need to switch to 32-bit mode? */ >> + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 >> + jnz call_32_bit > > Why do you need that? This is not needed because purgatory code > from kexec-tools always switches to 32-bit mode. Please check > kexec-tools/purgatory/arch/x86_64/entry64.S. The sub-architecture is a property of the image. Why should the tool know or care about the sub-architecture of the hypervisor? The ABI isn't designed only for kexec-tools. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-03-08 11:40 ` David Vrabel @ 2013-03-08 12:21 ` Daniel Kiper 2013-03-08 14:01 ` David Vrabel 0 siblings, 1 reply; 34+ messages in thread From: Daniel Kiper @ 2013-03-08 12:21 UTC (permalink / raw) To: David Vrabel; +Cc: kexec@lists.infradead.org, xen-devel@lists.xen.org On Fri, Mar 08, 2013 at 11:40:44AM +0000, David Vrabel wrote: > On 08/03/13 11:23, Daniel Kiper wrote: > > On Thu, Feb 21, 2013 at 05:48:11PM +0000, David Vrabel wrote: > >> > >> + /* Need to switch to 32-bit mode? */ > >> + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 > >> + jnz call_32_bit > > > > Why do you need that? This is not needed because purgatory code > > from kexec-tools always switches to 32-bit mode. Please check > > kexec-tools/purgatory/arch/x86_64/entry64.S. > > The sub-architecture is a property of the image. Why should the tool > know or care about the sub-architecture of the hypervisor? > > The ABI isn't designed only for kexec-tools. OK, but I think it is much easier to assume that machine state is not changed by kexec syscall/hypercall and move out this task to separate module (in this case purgatory code) which does all needed things (in this case sets it to "native" mode which is close to machine state after BIOS initialization; as I know this assumption is common for other architectures too). This way you could get what you need (e.g. 64-bit -> 64-bit, 64-bit -> 32-bit, ...) without changing a single instruction in hypervisor or kernel. Just do changes in purgatory (it could be called differently in your private kexec-tool) and voila. Additionally, you duplicate code which exists and works well. Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-03-08 12:21 ` Daniel Kiper @ 2013-03-08 14:01 ` David Vrabel 2013-03-08 15:23 ` Daniel Kiper 0 siblings, 1 reply; 34+ messages in thread From: David Vrabel @ 2013-03-08 14:01 UTC (permalink / raw) To: Daniel Kiper; +Cc: kexec@lists.infradead.org, xen-devel@lists.xen.org On 08/03/13 12:21, Daniel Kiper wrote: > On Fri, Mar 08, 2013 at 11:40:44AM +0000, David Vrabel wrote: >> On 08/03/13 11:23, Daniel Kiper wrote: >>> On Thu, Feb 21, 2013 at 05:48:11PM +0000, David Vrabel wrote: >>>> >>>> + /* Need to switch to 32-bit mode? */ >>>> + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 >>>> + jnz call_32_bit >>> >>> Why do you need that? This is not needed because purgatory code >>> from kexec-tools always switches to 32-bit mode. Please check >>> kexec-tools/purgatory/arch/x86_64/entry64.S. >> >> The sub-architecture is a property of the image. Why should the tool >> know or care about the sub-architecture of the hypervisor? >> >> The ABI isn't designed only for kexec-tools. > > OK, but I think it is much easier to assume that machine state > is not changed by kexec syscall/hypercall What machine state is that? The one seen by the tools or the guest kernel or by the hypervisor? The tools know what mode the image must be called it and it can tell the hypervisor and the hypervisor can trivial setup the correct mode. I propose: * Tools say: "here's an image, call it in mode X". You suggest: * Hypervisor implicitly says through some unspecified side channel: "I only call images in mode Y". * Tools says: "here's an image. I set it up for mode Y. I hope that works for you." Finally, the v1 interface will call images loaded by a 32-bit dom0 kernel in 32-bit mode and we need to do continue to do the same. > Additionally, you duplicate code which exists and works well. It's only 17 instructions and 6 bytes of data. David _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-03-08 14:01 ` David Vrabel @ 2013-03-08 15:23 ` Daniel Kiper 0 siblings, 0 replies; 34+ messages in thread From: Daniel Kiper @ 2013-03-08 15:23 UTC (permalink / raw) To: David Vrabel; +Cc: kexec@lists.infradead.org, xen-devel@lists.xen.org On Fri, Mar 08, 2013 at 02:01:19PM +0000, David Vrabel wrote: > On 08/03/13 12:21, Daniel Kiper wrote: > > On Fri, Mar 08, 2013 at 11:40:44AM +0000, David Vrabel wrote: > >> On 08/03/13 11:23, Daniel Kiper wrote: > >>> On Thu, Feb 21, 2013 at 05:48:11PM +0000, David Vrabel wrote: > >>>> > >>>> + /* Need to switch to 32-bit mode? */ > >>>> + testq $KEXEC_RELOC_FLAG_COMPAT, %r8 > >>>> + jnz call_32_bit > >>> > >>> Why do you need that? This is not needed because purgatory code > >>> from kexec-tools always switches to 32-bit mode. Please check > >>> kexec-tools/purgatory/arch/x86_64/entry64.S. > >> > >> The sub-architecture is a property of the image. Why should the tool > >> know or care about the sub-architecture of the hypervisor? > >> > >> The ABI isn't designed only for kexec-tools. > > > > OK, but I think it is much easier to assume that machine state > > is not changed by kexec syscall/hypercall > > What machine state is that? The one seen by the tools or the guest > kernel or by the hypervisor? State of machine set by hypervisor before purgatory call. > The tools know what mode the image must be called it and it can tell the > hypervisor and the hypervisor can trivial setup the correct mode. > > I propose: > > * Tools say: "here's an image, call it in mode X". > > You suggest: > > * Hypervisor implicitly says through some unspecified side channel: "I > only call images in mode Y". Purgatory is clearly defined. Please look into kexec-tools/purgatory. It is integral part of kexec infrastructure. > * Tools says: "here's an image. I set it up for mode Y. I hope that > works for you." New kernel is never called directly by old kernel in current kexec implementations. New system is always started in following way: old_kernel -> purgatory -> new_kernel What purgatory does I described earlier more or less. Why do you want change that? It works on many architectures. Why do we need something different for Xen (and Xen only)? If we choose existing solution we do not lose any flexiblity. Additionally, we could maintain compatibilty at least with Linux for nothing. > Finally, the v1 interface will call images loaded by a 32-bit dom0 > kernel in 32-bit mode and we need to do continue to do the same. Purgatory does it. It is used even with current Xen kexec implementation. > > Additionally, you duplicate code which exists and works well. > > It's only 17 instructions and 6 bytes of data. For me it is always worth to optimize code. In this case too. However, to be precise, if you remove this unneeded code then you could gain PAGE_SIZE - 1 bytes in worst case. Just remove .align PAGE_SIZE in xen/xen/arch/x86/x86_64/kexec_reloc.S. Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
* Re: [PATCH 5/8] kexec: extend hypercall with improved load/unload ops 2013-02-21 17:48 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel 2013-02-21 22:41 ` Daniel Kiper 2013-03-08 11:23 ` Daniel Kiper @ 2013-03-12 11:36 ` Daniel Kiper 2 siblings, 0 replies; 34+ messages in thread From: Daniel Kiper @ 2013-03-12 11:36 UTC (permalink / raw) To: David Vrabel; +Cc: kexec, xen-devel On Thu, Feb 21, 2013 at 05:48:11PM +0000, David Vrabel wrote: > From: David Vrabel <david.vrabel@citrix.com> > > In the existing kexec hypercall, the load and unload ops depend on > internals of the Linux kernel (the page list and code page provided by > the kernel). The code page is used to transition between Xen context > and the image so using kernel code doesn't make sense and will not > work for PVH guests. > > Add replacement KEXEC_CMD_kexec_load and KEXEC_CMD_kexec_unload ops > that no longer require a code page to be provided by the guest -- Xen > now provides the code for calling the image directly. > > The new load op looks similar to the Linux kexec_load system call and > allows the guest to provide the image data to be loaded. The guest > specifies the architecture of the image which may be a 32-bit subarch > of the hypervisor's architecture (i.e., an EM_386 image on an > EM_X86_64 hypervisor). > > The toolstack can now load images without kernel involvement. This is > required for supporting kexec when using a dom0 with an upstream > kernel. > > Crash images are copied directly into the crash region on load. > Default images are copied into Xen heap pages and a list of source and > destination machine addresses is created. This is list is used in > kexec_reloc() to relocate the image to its destination. > > The old load and unload sub-ops are still available (as > KEXEC_CMD_load_v1 and KEXEC_CMD_unload_v1) and are implemented on top > of the new infrastructure. > > Signed-off-by: David Vrabel <david.vrabel@citrix.com> [...] > diff --git a/xen/common/kexec.c b/xen/common/kexec.c [...] > -static int kexec_load_unload_compat(unsigned long op, > - XEN_GUEST_HANDLE_PARAM(void) uarg) > +static int kexec_load_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) > { > #ifdef CONFIG_COMPAT > compat_kexec_load_v1_t compat_load; > @@ -807,49 +990,113 @@ static int kexec_load_unload_compat(unsigned long op, > load.type = compat_load.type; > XLAT_kexec_image(&load.image, &compat_load.image); > > - return kexec_load_unload_internal(op, &load); > -#else /* CONFIG_COMPAT */ > + return kexec_do_load_v1(&load); > +#else > return 0; -ENOSYS? > -#endif /* CONFIG_COMPAT */ > +#endif > } [...] > +static int kexec_unload_v1_compat(XEN_GUEST_HANDLE_PARAM(void) uarg) > +{ > +#ifdef CONFIG_COMPAT > + compat_kexec_load_v1_t compat_load; > + xen_kexec_unload_t unload; > + > + if ( copy_from_guest(&compat_load, uarg, 1) ) > + return -EFAULT; > + > + unload.type = compat_load.type; > + return kexec_do_unload(&unload); > +#else > + return 0; -ENOSYS? > +#endif > +} ...and in other similar places... Daniel _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 34+ messages in thread
end of thread, other threads:[~2013-04-19 8:09 UTC | newest] Thread overview: 34+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2013-04-08 18:59 [PATCHv3 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel 2013-04-08 18:59 ` [PATCH 1/8] x86: give FIX_EFI_MPF its own fixmap entry David Vrabel 2013-04-09 7:27 ` [Xen-devel] " Jan Beulich 2013-04-09 16:15 ` David Vrabel 2013-04-08 18:59 ` [PATCH 2/8] xen: make GUEST_HANDLE_64() and uint64_aligned_t available everywhere David Vrabel 2013-04-08 18:59 ` [PATCH 3/8] kexec: add public interface for improved load/unload sub-ops David Vrabel 2013-04-09 7:32 ` [Xen-devel] " Jan Beulich 2013-04-12 11:56 ` David Vrabel 2013-04-12 13:01 ` Jan Beulich 2013-04-08 18:59 ` [PATCH 4/8] kexec: add infrastructure for handling kexec images David Vrabel 2013-04-09 7:44 ` [Xen-devel] " Jan Beulich 2013-04-09 16:17 ` David Vrabel 2013-04-10 8:36 ` Jan Beulich 2013-04-08 18:59 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel 2013-04-09 21:02 ` Daniel Kiper 2013-04-15 18:58 ` David Vrabel 2013-04-16 12:05 ` Daniel Kiper 2013-04-16 14:57 ` David Vrabel 2013-04-08 18:59 ` [PATCH 6/8] xen: kexec crash image when dom0 crashes David Vrabel 2013-04-09 21:11 ` Daniel Kiper 2013-04-08 18:59 ` [PATCH 7/8] libxc: add hypercall buffer arrays David Vrabel 2013-04-08 18:59 ` [PATCH 8/8] libxc: add API for kexec hypercall David Vrabel -- strict thread matches above, loose matches on Subject: below -- 2013-04-16 17:13 [PATCHv4 0/8] kexec: extend kexec hypercall for use with pv-ops kernels David Vrabel 2013-04-16 17:13 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel 2013-04-17 12:51 ` Daniel Kiper 2013-04-18 16:29 ` David Vrabel 2013-04-19 8:08 ` Daniel Kiper 2013-02-21 17:48 [PATCH 0/8] kexec: extended kexec hypercall for use with pv-ops kernels David Vrabel 2013-02-21 17:48 ` [PATCH 5/8] kexec: extend hypercall with improved load/unload ops David Vrabel 2013-02-21 22:41 ` Daniel Kiper 2013-03-08 11:23 ` Daniel Kiper 2013-03-08 11:40 ` David Vrabel 2013-03-08 12:21 ` Daniel Kiper 2013-03-08 14:01 ` David Vrabel 2013-03-08 15:23 ` Daniel Kiper 2013-03-12 11:36 ` Daniel Kiper
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