From 7e77506a5918d82cafa2ffa783ab57c23f9e9817 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Thu, 30 Sep 2010 12:37:26 +0100 Subject: xen: implement XENMEM_machphys_mapping This hypercall allows Xen to specify a non-default location for the machine to physical mapping. This capability is used when running a 32 bit domain 0 on a 64 bit hypervisor to shrink the hypervisor hole to exactly the size required. [ Impact: add Xen hypercall definitions ] Signed-off-by: Ian Campbell Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Stefano Stabellini --- arch/x86/include/asm/xen/interface.h | 6 +++--- arch/x86/include/asm/xen/interface_32.h | 5 +++++ arch/x86/include/asm/xen/interface_64.h | 13 +------------ arch/x86/include/asm/xen/page.h | 7 ++++--- arch/x86/xen/enlighten.c | 7 +++++++ arch/x86/xen/mmu.c | 14 ++++++++++++++ include/xen/interface/memory.h | 13 +++++++++++++ 7 files changed, 47 insertions(+), 18 deletions(-) diff --git a/arch/x86/include/asm/xen/interface.h b/arch/x86/include/asm/xen/interface.h index e8506c1f0c5..1c10c88ee4e 100644 --- a/arch/x86/include/asm/xen/interface.h +++ b/arch/x86/include/asm/xen/interface.h @@ -61,9 +61,9 @@ DEFINE_GUEST_HANDLE(void); #define HYPERVISOR_VIRT_START mk_unsigned_long(__HYPERVISOR_VIRT_START) #endif -#ifndef machine_to_phys_mapping -#define machine_to_phys_mapping ((unsigned long *)HYPERVISOR_VIRT_START) -#endif +#define MACH2PHYS_VIRT_START mk_unsigned_long(__MACH2PHYS_VIRT_START) +#define MACH2PHYS_VIRT_END mk_unsigned_long(__MACH2PHYS_VIRT_END) +#define MACH2PHYS_NR_ENTRIES ((MACH2PHYS_VIRT_END-MACH2PHYS_VIRT_START)>>__MACH2PHYS_SHIFT) /* Maximum number of virtual CPUs in multi-processor guests. */ #define MAX_VIRT_CPUS 32 diff --git a/arch/x86/include/asm/xen/interface_32.h b/arch/x86/include/asm/xen/interface_32.h index 42a7e004ae5..8413688b257 100644 --- a/arch/x86/include/asm/xen/interface_32.h +++ b/arch/x86/include/asm/xen/interface_32.h @@ -32,6 +32,11 @@ /* And the trap vector is... */ #define TRAP_INSTR "int $0x82" +#define __MACH2PHYS_VIRT_START 0xF5800000 +#define __MACH2PHYS_VIRT_END 0xF6800000 + +#define __MACH2PHYS_SHIFT 2 + /* * Virtual addresses beyond this are not modifiable by guest OSes. The * machine->physical mapping table starts at this address, read-only. diff --git a/arch/x86/include/asm/xen/interface_64.h b/arch/x86/include/asm/xen/interface_64.h index 100d2662b97..839a4811cf9 100644 --- a/arch/x86/include/asm/xen/interface_64.h +++ b/arch/x86/include/asm/xen/interface_64.h @@ -39,18 +39,7 @@ #define __HYPERVISOR_VIRT_END 0xFFFF880000000000 #define __MACH2PHYS_VIRT_START 0xFFFF800000000000 #define __MACH2PHYS_VIRT_END 0xFFFF804000000000 - -#ifndef HYPERVISOR_VIRT_START -#define HYPERVISOR_VIRT_START mk_unsigned_long(__HYPERVISOR_VIRT_START) -#define HYPERVISOR_VIRT_END mk_unsigned_long(__HYPERVISOR_VIRT_END) -#endif - -#define MACH2PHYS_VIRT_START mk_unsigned_long(__MACH2PHYS_VIRT_START) -#define MACH2PHYS_VIRT_END mk_unsigned_long(__MACH2PHYS_VIRT_END) -#define MACH2PHYS_NR_ENTRIES ((MACH2PHYS_VIRT_END-MACH2PHYS_VIRT_START)>>3) -#ifndef machine_to_phys_mapping -#define machine_to_phys_mapping ((unsigned long *)HYPERVISOR_VIRT_START) -#endif +#define __MACH2PHYS_SHIFT 3 /* * int HYPERVISOR_set_segment_base(unsigned int which, unsigned long base) diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index dd8c1414b3d..8760cc60a21 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -5,6 +5,7 @@ #include #include #include +#include #include #include @@ -35,6 +36,8 @@ typedef struct xpaddr { #define MAX_DOMAIN_PAGES \ ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE)) +extern unsigned long *machine_to_phys_mapping; +extern unsigned int machine_to_phys_order; extern unsigned long get_phys_to_machine(unsigned long pfn); extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn); @@ -69,10 +72,8 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn) if (xen_feature(XENFEAT_auto_translated_physmap)) return mfn; -#if 0 if (unlikely((mfn >> machine_to_phys_order) != 0)) - return max_mapnr; -#endif + return ~0; pfn = 0; /* diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 235c0f4d386..bd355493461 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -75,6 +75,11 @@ DEFINE_PER_CPU(struct vcpu_info, xen_vcpu_info); enum xen_domain_type xen_domain_type = XEN_NATIVE; EXPORT_SYMBOL_GPL(xen_domain_type); +unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START; +EXPORT_SYMBOL(machine_to_phys_mapping); +unsigned int machine_to_phys_order; +EXPORT_SYMBOL(machine_to_phys_order); + struct start_info *xen_start_info; EXPORT_SYMBOL_GPL(xen_start_info); @@ -1097,6 +1102,8 @@ asmlinkage void __init xen_start_kernel(void) xen_domain_type = XEN_PV_DOMAIN; + xen_setup_machphys_mapping(); + /* Install Xen paravirt ops */ pv_info = xen_info; pv_init_ops = xen_init_ops; diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c index 21ed8d7f75a..bd2713a8257 100644 --- a/arch/x86/xen/mmu.c +++ b/arch/x86/xen/mmu.c @@ -2034,6 +2034,20 @@ static __init void xen_map_identity_early(pmd_t *pmd, unsigned long max_pfn) set_page_prot(pmd, PAGE_KERNEL_RO); } +void __init xen_setup_machphys_mapping(void) +{ + struct xen_machphys_mapping mapping; + unsigned long machine_to_phys_nr_ents; + + if (HYPERVISOR_memory_op(XENMEM_machphys_mapping, &mapping) == 0) { + machine_to_phys_mapping = (unsigned long *)mapping.v_start; + machine_to_phys_nr_ents = mapping.max_mfn + 1; + } else { + machine_to_phys_nr_ents = MACH2PHYS_NR_ENTRIES; + } + machine_to_phys_order = fls(machine_to_phys_nr_ents - 1); +} + #ifdef CONFIG_X86_64 static void convert_pfn_mfn(void *v) { diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h index d7a6c13bde6..eac3ce15371 100644 --- a/include/xen/interface/memory.h +++ b/include/xen/interface/memory.h @@ -140,6 +140,19 @@ struct xen_machphys_mfn_list { }; DEFINE_GUEST_HANDLE_STRUCT(xen_machphys_mfn_list); +/* + * Returns the location in virtual address space of the machine_to_phys + * mapping table. Architectures which do not have a m2p table, or which do not + * map it by default into guest address space, do not implement this command. + * arg == addr of xen_machphys_mapping_t. + */ +#define XENMEM_machphys_mapping 12 +struct xen_machphys_mapping { + unsigned long v_start, v_end; /* Start and end virtual addresses. */ + unsigned long max_mfn; /* Maximum MFN that can be looked up. */ +}; +DEFINE_GUEST_HANDLE_STRUCT(xen_machphys_mapping_t); + /* * Sets the GPFN at which a particular page appears in the specified guest's * pseudophysical address space. -- cgit v1.2.3