[PATCHv2 0/2] Linux PVH dom0 memory setup

[PATCHv2 0/2] Linux PVH dom0 memory setup

[David Vrabel]

This is an patch fixing up Linux's memory setup for PVH dom0 after the
recent Xen change (x86: fix setup of PVH Dom0 memory map).

Changes in v2:
- panic if no memory map
- sanitize e820
- reserve start info bits and pieces

David

[PATCH 1/2] x86/xen: fix memory setup for PVH dom0

[David Vrabel]

Since af06d66ee32b (x86: fix setup of PVH Dom0 memory map) in Xen, PVH
dom0 need only use the memory memory provided by Xen which has already
setup all the correct holes.

xen_memory_setup() then ends up being trivial for a PVH guest so
introduce a new function (xen_auto_xlated_memory_setup()).

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
 arch/x86/xen/enlighten.c |    5 ++++-
 arch/x86/xen/setup.c     |   29 +++++++++++++++++++++++++++++
 arch/x86/xen/xen-ops.h   |    1 +
 3 files changed, 34 insertions(+), 1 deletion(-)

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index c34bfc4..7dffa8c 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1536,7 +1536,10 @@ asmlinkage __visible void __init xen_start_kernel(void)
 	if (!xen_pvh_domain())
 		pv_cpu_ops = xen_cpu_ops;
 
-	x86_init.resources.memory_setup = xen_memory_setup;
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		x86_init.resources.memory_setup = xen_auto_xlated_memory_setup;
+	else
+		x86_init.resources.memory_setup = xen_memory_setup;
 	x86_init.oem.arch_setup = xen_arch_setup;
 	x86_init.oem.banner = xen_banner;
 
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index 0982233..d54d686 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -509,6 +509,35 @@ char * __init xen_memory_setup(void)
 }
 
 /*
+ * Machine specific memory setup for auto-translated guests.
+ */
+char * __init xen_auto_xlated_memory_setup(void)
+{
+	static struct e820entry map[E820MAX] __initdata;
+
+	struct xen_memory_map memmap;
+	int i;
+	int rc;
+
+	memmap.nr_entries = E820MAX;
+	set_xen_guest_handle(memmap.buffer, map);
+
+	rc = HYPERVISOR_memory_op(XENMEM_memory_map, &memmap);
+	if (rc < 0)
+		panic("No memory map (%d)\n", rc);
+
+	sanitize_e820_map(map, ARRAY_SIZE(map), &memmap.nr_entries);
+
+	for (i = 0; i < memmap.nr_entries; i++)
+		e820_add_region(map[i].addr, map[i].size, map[i].type);
+
+	memblock_reserve(__pa(xen_start_info->mfn_list),
+			 xen_start_info->pt_base - xen_start_info->mfn_list);
+
+	return "Xen";
+}
+
+/*
  * Set the bit indicating "nosegneg" library variants should be used.
  * We only need to bother in pure 32-bit mode; compat 32-bit processes
  * can have un-truncated segments, so wrapping around is allowed.
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 1cb6f4c..b371d18 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -34,6 +34,7 @@ extern unsigned long xen_max_p2m_pfn;
 void xen_set_pat(u64);
 
 char * __init xen_memory_setup(void);
+char * xen_auto_xlated_memory_setup(void);
 void __init xen_arch_setup(void);
 void xen_enable_sysenter(void);
 void xen_enable_syscall(void);
-- 
1.7.10.4

[PATCH 2/2] Revert "xen/pvh: Update E820 to work with PVH (v2)"

[David Vrabel]

This reverts commit 9103bb0f8240b2a55aac3ff7ecba9c7dcf66b08b.

Now than xen_memory_setup() is not called for auto-translated guests,
we can remove this commit.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
---
 arch/x86/xen/setup.c |   22 ++--------------------
 1 file changed, 2 insertions(+), 20 deletions(-)

diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index d54d686..039b9c5 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -27,7 +27,6 @@
 #include <xen/interface/memory.h>
 #include <xen/interface/physdev.h>
 #include <xen/features.h>
-#include "mmu.h"
 #include "xen-ops.h"
 #include "vdso.h"
 
@@ -82,9 +81,6 @@ static void __init xen_add_extra_mem(u64 start, u64 size)
 
 	memblock_reserve(start, size);
 
-	if (xen_feature(XENFEAT_auto_translated_physmap))
-		return;
-
 	xen_max_p2m_pfn = PFN_DOWN(start + size);
 	for (pfn = PFN_DOWN(start); pfn < xen_max_p2m_pfn; pfn++) {
 		unsigned long mfn = pfn_to_mfn(pfn);
@@ -107,7 +103,6 @@ static unsigned long __init xen_do_chunk(unsigned long start,
 		.domid        = DOMID_SELF
 	};
 	unsigned long len = 0;
-	int xlated_phys = xen_feature(XENFEAT_auto_translated_physmap);
 	unsigned long pfn;
 	int ret;
 
@@ -121,7 +116,7 @@ static unsigned long __init xen_do_chunk(unsigned long start,
 				continue;
 			frame = mfn;
 		} else {
-			if (!xlated_phys && mfn != INVALID_P2M_ENTRY)
+			if (mfn != INVALID_P2M_ENTRY)
 				continue;
 			frame = pfn;
 		}
@@ -159,13 +154,6 @@ static unsigned long __init xen_do_chunk(unsigned long start,
 static unsigned long __init xen_release_chunk(unsigned long start,
 					      unsigned long end)
 {
-	/*
-	 * Xen already ballooned out the E820 non RAM regions for us
-	 * and set them up properly in EPT.
-	 */
-	if (xen_feature(XENFEAT_auto_translated_physmap))
-		return end - start;
-
 	return xen_do_chunk(start, end, true);
 }
 
@@ -234,13 +222,7 @@ static void __init xen_set_identity_and_release_chunk(
 	 * (except for the ISA region which must be 1:1 mapped) to
 	 * release the refcounts (in Xen) on the original frames.
 	 */
-
-	/*
-	 * PVH E820 matches the hypervisor's P2M which means we need to
-	 * account for the proper values of *release and *identity.
-	 */
-	for (pfn = start_pfn; !xen_feature(XENFEAT_auto_translated_physmap) &&
-	     pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) {
+	for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) {
 		pte_t pte = __pte_ma(0);
 
 		if (pfn < PFN_UP(ISA_END_ADDRESS))
-- 
1.7.10.4

Re: [PATCHv2 0/2] Linux PVH dom0 memory setup

[Roger Pau Monné]

On 05/06/14 13:51, David Vrabel wrote:
> This is an patch fixing up Linux's memory setup for PVH dom0 after the
> recent Xen change (x86: fix setup of PVH Dom0 memory map).
> 
> Changes in v2:
> - panic if no memory map
> - sanitize e820
> - reserve start info bits and pieces

For both:

Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Tested-by: Roger Pau Monné <roger.pau@citrix.com>

Re: [PATCHv2 0/2] Linux PVH dom0 memory setup

[David Vrabel]

On 05/06/14 14:19, Roger Pau Monné wrote:
> On 05/06/14 13:51, David Vrabel wrote:
>> This is an patch fixing up Linux's memory setup for PVH dom0 after the
>> recent Xen change (x86: fix setup of PVH Dom0 memory map).
>>
>> Changes in v2:
>> - panic if no memory map
>> - sanitize e820
>> - reserve start info bits and pieces
> 
> For both:
> 
> Acked-by: Roger Pau Monné <roger.pau@citrix.com>
> Tested-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks.  Applied to stable/for-linus-3.16

David