[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4 1/7] x86: provide executable fixmap facility
This allows us to set aside some address space for executable mapping. This fixed map range starts from XEN_VIRT_END so that it is within reach of the .text section. Shift the percpu stub range and livepatch range accordingly. Signed-off-by: Wei Liu <liuwe@xxxxxxxxxxxxx> --- xen/arch/x86/boot/x86_64.S | 10 +++++++++- xen/arch/x86/livepatch.c | 3 ++- xen/arch/x86/mm.c | 9 +++++++++ xen/arch/x86/smpboot.c | 2 +- xen/arch/x86/xen.lds.S | 3 +++ xen/include/asm-x86/config.h | 2 +- xen/include/asm-x86/fixmap.h | 28 ++++++++++++++++++++++++++++ 7 files changed, 53 insertions(+), 4 deletions(-) diff --git a/xen/arch/x86/boot/x86_64.S b/xen/arch/x86/boot/x86_64.S index 1cbf5acdfb..605d01f1dd 100644 --- a/xen/arch/x86/boot/x86_64.S +++ b/xen/arch/x86/boot/x86_64.S @@ -85,7 +85,15 @@ GLOBAL(l2_directmap) * 4k page. */ GLOBAL(l2_xenmap) - .fill L2_PAGETABLE_ENTRIES, 8, 0 + idx = 0 + .rept L2_PAGETABLE_ENTRIES + .if idx == l2_table_offset(FIXADDR_X_TOP - 1) + .quad sym_offs(l1_fixmap_x) + __PAGE_HYPERVISOR + .else + .quad 0 + .endif + idx = idx + 1 + .endr .size l2_xenmap, . - l2_xenmap /* L2 mapping the fixmap. Uses 1x 4k page. */ diff --git a/xen/arch/x86/livepatch.c b/xen/arch/x86/livepatch.c index 2749cbc5cf..513b0f3841 100644 --- a/xen/arch/x86/livepatch.c +++ b/xen/arch/x86/livepatch.c @@ -12,6 +12,7 @@ #include <xen/livepatch.h> #include <xen/sched.h> +#include <asm/fixmap.h> #include <asm/nmi.h> #include <asm/livepatch.h> @@ -311,7 +312,7 @@ void __init arch_livepatch_init(void) void *start, *end; start = (void *)xen_virt_end; - end = (void *)(XEN_VIRT_END - NR_CPUS * PAGE_SIZE); + end = (void *)(XEN_VIRT_END - FIXADDR_X_SIZE - NR_CPUS * PAGE_SIZE); BUG_ON(end <= start); diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 654190e9e9..aabe1a4c64 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -157,6 +157,8 @@ /* Mapping of the fixmap space needed early. */ l1_pgentry_t __section(".bss.page_aligned") __aligned(PAGE_SIZE) l1_fixmap[L1_PAGETABLE_ENTRIES]; +l1_pgentry_t __section(".bss.page_aligned") __aligned(PAGE_SIZE) + l1_fixmap_x[L1_PAGETABLE_ENTRIES]; paddr_t __read_mostly mem_hotplug; @@ -5763,6 +5765,13 @@ void __set_fixmap( map_pages_to_xen(__fix_to_virt(idx), _mfn(mfn), 1, flags); } +void __set_fixmap_x( + enum fixed_addresses_x idx, unsigned long mfn, unsigned long flags) +{ + BUG_ON(idx >= __end_of_fixed_addresses_x); + map_pages_to_xen(__fix_x_to_virt(idx), _mfn(mfn), 1, flags); +} + void *__init arch_vmap_virt_end(void) { return fix_to_virt(__end_of_fixed_addresses); diff --git a/xen/arch/x86/smpboot.c b/xen/arch/x86/smpboot.c index c9d1ab4423..2da42fb691 100644 --- a/xen/arch/x86/smpboot.c +++ b/xen/arch/x86/smpboot.c @@ -640,7 +640,7 @@ unsigned long alloc_stub_page(unsigned int cpu, unsigned long *mfn) unmap_domain_page(memset(__map_domain_page(pg), 0xcc, PAGE_SIZE)); } - stub_va = XEN_VIRT_END - (cpu + 1) * PAGE_SIZE; + stub_va = XEN_VIRT_END - FIXADDR_X_SIZE - (cpu + 1) * PAGE_SIZE; if ( map_pages_to_xen(stub_va, page_to_mfn(pg), 1, PAGE_HYPERVISOR_RX | MAP_SMALL_PAGES) ) { diff --git a/xen/arch/x86/xen.lds.S b/xen/arch/x86/xen.lds.S index 07c6448dbb..cbc5701214 100644 --- a/xen/arch/x86/xen.lds.S +++ b/xen/arch/x86/xen.lds.S @@ -3,6 +3,8 @@ #include <xen/cache.h> #include <xen/lib.h> + +#include <asm/fixmap.h> #include <asm/page.h> #undef ENTRY #undef ALIGN @@ -353,6 +355,7 @@ SECTIONS } ASSERT(__2M_rwdata_end <= XEN_VIRT_END - XEN_VIRT_START + __XEN_VIRT_START - + MAX_FIXADDR_X_SIZE - DIV_ROUND_UP(NR_CPUS, STUBS_PER_PAGE) * PAGE_SIZE, "Xen image overlaps stubs area") diff --git a/xen/include/asm-x86/config.h b/xen/include/asm-x86/config.h index d0cfbb70a8..4fa56ea0a9 100644 --- a/xen/include/asm-x86/config.h +++ b/xen/include/asm-x86/config.h @@ -218,7 +218,7 @@ extern unsigned char boot_edid_info[128]; /* Slot 261: high read-only compat machine-to-phys conversion table (1GB). */ #define HIRO_COMPAT_MPT_VIRT_START RDWR_COMPAT_MPT_VIRT_END #define HIRO_COMPAT_MPT_VIRT_END (HIRO_COMPAT_MPT_VIRT_START + GB(1)) -/* Slot 261: xen text, static data and bss (1GB). */ +/* Slot 261: xen text, static data, bss and executable fixmap (1GB). */ #define XEN_VIRT_START (HIRO_COMPAT_MPT_VIRT_END) #define XEN_VIRT_END (XEN_VIRT_START + GB(1)) diff --git a/xen/include/asm-x86/fixmap.h b/xen/include/asm-x86/fixmap.h index 9fb2f47946..c2a9d2b50a 100644 --- a/xen/include/asm-x86/fixmap.h +++ b/xen/include/asm-x86/fixmap.h @@ -15,6 +15,9 @@ #include <asm/page.h> #define FIXADDR_TOP (VMAP_VIRT_END - PAGE_SIZE) +#define FIXADDR_X_TOP (XEN_VIRT_END - PAGE_SIZE) +/* This constant is derived from enum fixed_addresses_x below */ +#define MAX_FIXADDR_X_SIZE (2 << PAGE_SHIFT) #ifndef __ASSEMBLY__ @@ -89,6 +92,31 @@ static inline unsigned long virt_to_fix(const unsigned long vaddr) return __virt_to_fix(vaddr); } +enum fixed_addresses_x { + /* Index 0 is reserved since fix_x_to_virt(0) == FIXADDR_X_TOP. */ + FIX_X_RESERVED, +#ifdef CONFIG_HYPERV_GUEST + FIX_X_HYPERV_HCALL, +#endif + __end_of_fixed_addresses_x +}; + +#define FIXADDR_X_SIZE (__end_of_fixed_addresses_x << PAGE_SHIFT) +#define FIXADDR_X_START (FIXADDR_X_TOP - FIXADDR_X_SIZE) + +extern void __set_fixmap_x( + enum fixed_addresses_x idx, unsigned long mfn, unsigned long flags); + +#define set_fixmap_x(idx, phys) \ + __set_fixmap_x(idx, (phys)>>PAGE_SHIFT, PAGE_HYPERVISOR_RX | MAP_SMALL_PAGES) + +#define clear_fixmap_x(idx) __set_fixmap_x(idx, 0, 0) + +#define __fix_x_to_virt(x) (FIXADDR_X_TOP - ((x) << PAGE_SHIFT)) +#define __virt_to_fix_x(x) ((FIXADDR_X_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) + +#define fix_x_to_virt(x) ((void *)__fix_x_to_virt(x)) + #endif /* __ASSEMBLY__ */ #endif -- 2.20.1 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxxx https://lists.xenproject.org/mailman/listinfo/xen-devel
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