Re: [Xen-devel] [PATCH 01/24] arm: initial Xen support

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

On Thu, Jul 26, 2012 at 04:33:43PM +0100, Stefano Stabellini wrote:
> - Basic hypervisor.h and interface.h definitions.
> - Skelethon enlighten.c, set xen_start_info to an empty struct.

Skeleton

> - Do not limit xen_initial_domain to PV guests.

Better wording: Make xen_initial_domain dependent on the SIF_PRIVILIGED_BIT.

Which reminds me - what about PV guests that do PCI passthrough. Aren't
they "more" priviligied than normal PV guests? Or not really?
> 
> The new code only compiles when CONFIG_XEN is set, that is going to be
> added to arch/arm/Kconfig in a later patch.

s/later patch/<name of patch>/

> 
> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
> ---
>  arch/arm/Makefile                     |    1 +
>  arch/arm/include/asm/hypervisor.h     |    6 +++
>  arch/arm/include/asm/xen/hypervisor.h |   19 ++++++++++
>  arch/arm/include/asm/xen/interface.h  |   64 +++++++++++++++++++++++++++++++++
>  arch/arm/xen/Makefile                 |    1 +
>  arch/arm/xen/enlighten.c              |   35 ++++++++++++++++++
>  include/xen/xen.h                     |    2 +-
>  7 files changed, 127 insertions(+), 1 deletions(-)
>  create mode 100644 arch/arm/include/asm/hypervisor.h
>  create mode 100644 arch/arm/include/asm/xen/hypervisor.h
>  create mode 100644 arch/arm/include/asm/xen/interface.h
>  create mode 100644 arch/arm/xen/Makefile
>  create mode 100644 arch/arm/xen/enlighten.c
> 
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index 0298b00..70aaa82 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -246,6 +246,7 @@ endif
>  core-$(CONFIG_FPE_NWFPE)	+= arch/arm/nwfpe/
>  core-$(CONFIG_FPE_FASTFPE)	+= $(FASTFPE_OBJ)
>  core-$(CONFIG_VFP)		+= arch/arm/vfp/
> +core-$(CONFIG_XEN)		+= arch/arm/xen/
>  
>  # If we have a machine-specific directory, then include it in the build.
>  core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
> diff --git a/arch/arm/include/asm/hypervisor.h b/arch/arm/include/asm/hypervisor.h
> new file mode 100644
> index 0000000..b90d9e5
> --- /dev/null
> +++ b/arch/arm/include/asm/hypervisor.h
> @@ -0,0 +1,6 @@
> +#ifndef _ASM_ARM_HYPERVISOR_H
> +#define _ASM_ARM_HYPERVISOR_H
> +
> +#include <asm/xen/hypervisor.h>
> +
> +#endif
> diff --git a/arch/arm/include/asm/xen/hypervisor.h b/arch/arm/include/asm/xen/hypervisor.h
> new file mode 100644
> index 0000000..d7ab99a
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/hypervisor.h
> @@ -0,0 +1,19 @@
> +#ifndef _ASM_ARM_XEN_HYPERVISOR_H
> +#define _ASM_ARM_XEN_HYPERVISOR_H
> +
> +extern struct shared_info *HYPERVISOR_shared_info;
> +extern struct start_info *xen_start_info;
> +
> +/* Lazy mode for batching updates / context switch */
> +enum paravirt_lazy_mode {
> +	PARAVIRT_LAZY_NONE,
> +	PARAVIRT_LAZY_MMU,
> +	PARAVIRT_LAZY_CPU,
> +};
> +
> +static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
> +{
> +	return PARAVIRT_LAZY_NONE;
> +}
> +
> +#endif /* _ASM_ARM_XEN_HYPERVISOR_H */
> diff --git a/arch/arm/include/asm/xen/interface.h b/arch/arm/include/asm/xen/interface.h
> new file mode 100644
> index 0000000..6c3ab59
> --- /dev/null
> +++ b/arch/arm/include/asm/xen/interface.h
> @@ -0,0 +1,64 @@
> +/******************************************************************************
> + * Guest OS interface to ARM Xen.
> + *
> + * Stefano Stabellini <stefano.stabellini@eu.citrix.com>, Citrix, 2011

2012

> + */
> +
> +#ifndef _ASM_ARM_XEN_INTERFACE_H
> +#define _ASM_ARM_XEN_INTERFACE_H
> +
> +#include <linux/types.h>
> +
> +#define __DEFINE_GUEST_HANDLE(name, type) \
> +	typedef type * __guest_handle_ ## name
> +
> +#define DEFINE_GUEST_HANDLE_STRUCT(name) \
> +	__DEFINE_GUEST_HANDLE(name, struct name)
> +#define DEFINE_GUEST_HANDLE(name) __DEFINE_GUEST_HANDLE(name, name)
> +#define GUEST_HANDLE(name)        __guest_handle_ ## name
> +
> +#define set_xen_guest_handle(hnd, val)			\
> +	do {						\
> +		if (sizeof(hnd) == 8)			\
> +			*(uint64_t *)&(hnd) = 0;	\
> +		(hnd) = val;				\
> +	} while (0)
> +
> +#ifndef __ASSEMBLY__
> +/* Guest handles for primitive C types. */
> +__DEFINE_GUEST_HANDLE(uchar, unsigned char);
> +__DEFINE_GUEST_HANDLE(uint,  unsigned int);
> +__DEFINE_GUEST_HANDLE(ulong, unsigned long);
> +DEFINE_GUEST_HANDLE(char);
> +DEFINE_GUEST_HANDLE(int);
> +DEFINE_GUEST_HANDLE(long);
> +DEFINE_GUEST_HANDLE(void);
> +DEFINE_GUEST_HANDLE(uint64_t);
> +DEFINE_GUEST_HANDLE(uint32_t);
> +
> +/* Maximum number of virtual CPUs in multi-processor guests. */
> +#define MAX_VIRT_CPUS 1
> +
> +struct arch_vcpu_info { };
> +struct arch_shared_info { };
> +
> +/* XXX: Move pvclock definitions some place arch independent */
> +struct pvclock_vcpu_time_info {
> +	u32   version;
> +	u32   pad0;
> +	u64   tsc_timestamp;
> +	u64   system_time;
> +	u32   tsc_to_system_mul;
> +	s8    tsc_shift;
> +	u8    flags;
> +	u8    pad[2];
> +} __attribute__((__packed__)); /* 32 bytes */
> +
> +struct pvclock_wall_clock {
> +	u32   version;
> +	u32   sec;
> +	u32   nsec;
> +} __attribute__((__packed__));

That is weird. It is 4+4+4 = 12 bytes? Don't you want it to be 16 bytes?

> +#endif
> +
> +#endif /* _ASM_ARM_XEN_INTERFACE_H */
> diff --git a/arch/arm/xen/Makefile b/arch/arm/xen/Makefile
> new file mode 100644
> index 0000000..0bad594
> --- /dev/null
> +++ b/arch/arm/xen/Makefile
> @@ -0,0 +1 @@
> +obj-y		:= enlighten.o
> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
> new file mode 100644
> index 0000000..d27c2a6
> --- /dev/null
> +++ b/arch/arm/xen/enlighten.c
> @@ -0,0 +1,35 @@
> +#include <xen/xen.h>
> +#include <xen/interface/xen.h>
> +#include <xen/interface/memory.h>
> +#include <xen/platform_pci.h>
> +#include <asm/xen/hypervisor.h>
> +#include <asm/xen/hypercall.h>
> +#include <linux/module.h>
> +
> +struct start_info _xen_start_info;
> +struct start_info *xen_start_info = &_xen_start_info;
> +EXPORT_SYMBOL_GPL(xen_start_info);
> +
> +enum xen_domain_type xen_domain_type = XEN_NATIVE;
> +EXPORT_SYMBOL_GPL(xen_domain_type);
> +
> +struct shared_info xen_dummy_shared_info;
> +struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
> +
> +DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
> +
> +/* XXX: to be removed */

In this patch series later on? Or just when you try to collapse the x86 and arm variant
together?

> +__read_mostly int xen_have_vector_callback;
> +EXPORT_SYMBOL_GPL(xen_have_vector_callback);
> +
> +int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
> +EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
> +
> +int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
> +			       unsigned long addr,
> +			       unsigned long mfn, int nr,
> +			       pgprot_t prot, unsigned domid)
> +{
> +	return -ENOSYS;
> +}
> +EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
> diff --git a/include/xen/xen.h b/include/xen/xen.h
> index a164024..2c0d3a5 100644
> --- a/include/xen/xen.h
> +++ b/include/xen/xen.h
> @@ -23,7 +23,7 @@ extern enum xen_domain_type xen_domain_type;
>  #include <xen/interface/xen.h>
>  #include <asm/xen/hypervisor.h>
>  
> -#define xen_initial_domain()	(xen_pv_domain() && \
> +#define xen_initial_domain()	(xen_domain() && \
>  				 xen_start_info->flags & SIF_INITDOMAIN)
>  #else  /* !CONFIG_XEN_DOM0 */
>  #define xen_initial_domain()	(0)
> -- 
> 1.7.2.5
> 
> 
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