[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen stable-4.5] x86: fix (and simplify) MTRR overlap checking
commit 677eb6e2dc5295ea49d6d75971c96695567ae601 Author: Jan Beulich <jbeulich@xxxxxxxx> AuthorDate: Wed Feb 17 16:46:52 2016 +0100 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Wed Feb 17 16:46:52 2016 +0100 x86: fix (and simplify) MTRR overlap checking Obtaining one individual range per variable range register (via get_mtrr_range()) was bogus from the beginning, as these registers may cover multiple disjoint ranges. Do away with that, in favor of simply comparing masked addresses. Also, for is_var_mtrr_overlapped()'s result to be correct when called from mtrr_wrmsr(), generic_set_mtrr() must update saved state first. As minor cleanup changes, constify is_var_mtrr_overlapped()'s parameter and make mtrr_wrmsr() static. Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx> Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx> master commit: 3272230848f36eb5bbb660216898a90048a81d9f master date: 2016-01-21 16:11:04 +0100 --- xen/arch/x86/cpu/mtrr/generic.c | 4 +-- xen/arch/x86/cpu/mtrr/mtrr.h | 1 - xen/arch/x86/hvm/mtrr.c | 61 ++++++++--------------------------------- xen/include/asm-x86/mtrr.h | 2 +- 4 files changed, 15 insertions(+), 53 deletions(-) diff --git a/xen/arch/x86/cpu/mtrr/generic.c b/xen/arch/x86/cpu/mtrr/generic.c index 493830b..9f96e5c 100644 --- a/xen/arch/x86/cpu/mtrr/generic.c +++ b/xen/arch/x86/cpu/mtrr/generic.c @@ -208,7 +208,7 @@ void __init mtrr_state_warn(void) /* Doesn't attempt to pass an error out to MTRR users because it's quite complicated in some cases and probably not worth it because the best error handling is to ignore it. */ -void mtrr_wrmsr(unsigned int msr, uint64_t msr_content) +static void mtrr_wrmsr(unsigned int msr, uint64_t msr_content) { if (wrmsr_safe(msr, msr_content) < 0) printk(KERN_ERR @@ -483,8 +483,8 @@ static void generic_set_mtrr(unsigned int reg, unsigned long base, if (size == 0) { /* The invalid bit is kept in the mask, so we simply clear the relevant mask register to disable a range. */ + memset(vr, 0, sizeof(*vr)); mtrr_wrmsr(MSR_IA32_MTRR_PHYSMASK(reg), 0); - memset(vr, 0, sizeof(struct mtrr_var_range)); } else { uint32_t base_lo, base_hi, mask_lo, mask_hi; diff --git a/xen/arch/x86/cpu/mtrr/mtrr.h b/xen/arch/x86/cpu/mtrr/mtrr.h index a9d6dcd..b41eb58 100644 --- a/xen/arch/x86/cpu/mtrr/mtrr.h +++ b/xen/arch/x86/cpu/mtrr/mtrr.h @@ -63,7 +63,6 @@ extern const struct mtrr_ops *mtrr_if; extern unsigned int num_var_ranges; void mtrr_state_warn(void); -void mtrr_wrmsr(unsigned int msr, uint64_t msr_content); extern int amd_init_mtrr(void); extern int cyrix_init_mtrr(void); diff --git a/xen/arch/x86/hvm/mtrr.c b/xen/arch/x86/hvm/mtrr.c index aa6e25b..35adbf5 100644 --- a/xen/arch/x86/hvm/mtrr.c +++ b/xen/arch/x86/hvm/mtrr.c @@ -29,8 +29,6 @@ #include <asm/hvm/support.h> #include <asm/hvm/cacheattr.h> -static uint32_t size_or_mask; - /* Get page attribute fields (PAn) from PAT MSR. */ #define pat_cr_2_paf(pat_cr,n) ((((uint64_t)pat_cr) >> ((n)<<3)) & 0xff) @@ -80,61 +78,28 @@ static uint8_t __read_mostly mtrr_epat_tbl[MTRR_NUM_TYPES][MEMORY_NUM_TYPES] = static uint8_t __read_mostly pat_entry_tbl[PAT_TYPE_NUMS] = { [0 ... PAT_TYPE_NUMS-1] = INVALID_MEM_TYPE }; -static void get_mtrr_range(uint64_t base_msr, uint64_t mask_msr, - uint64_t *base, uint64_t *end) -{ - uint32_t mask_lo = (uint32_t)mask_msr; - uint32_t mask_hi = (uint32_t)(mask_msr >> 32); - uint32_t base_lo = (uint32_t)base_msr; - uint32_t base_hi = (uint32_t)(base_msr >> 32); - uint32_t size; - - if ( !(mask_lo & MTRR_PHYSMASK_VALID) ) - { - /* Invalid (i.e. free) range */ - *base = 0; - *end = 0; - return; - } - - /* Work out the shifted address mask. */ - mask_lo = (size_or_mask | (mask_hi << (32 - PAGE_SHIFT)) | - (mask_lo >> PAGE_SHIFT)); - - /* This works correctly if size is a power of two (a contiguous range). */ - size = -mask_lo; - *base = base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT; - *end = *base + size - 1; -} - -bool_t is_var_mtrr_overlapped(struct mtrr_state *m) +bool_t is_var_mtrr_overlapped(const struct mtrr_state *m) { - int32_t seg, i; - uint64_t phys_base, phys_mask, phys_base_pre, phys_mask_pre; - uint64_t base_pre, end_pre, base, end; - uint8_t num_var_ranges = (uint8_t)m->mtrr_cap; + unsigned int seg, i; + unsigned int num_var_ranges = (uint8_t)m->mtrr_cap; for ( i = 0; i < num_var_ranges; i++ ) { - phys_base_pre = ((uint64_t*)m->var_ranges)[i*2]; - phys_mask_pre = ((uint64_t*)m->var_ranges)[i*2 + 1]; + uint64_t base1 = m->var_ranges[i].base >> PAGE_SHIFT; + uint64_t mask1 = m->var_ranges[i].mask >> PAGE_SHIFT; - get_mtrr_range(phys_base_pre, phys_mask_pre, - &base_pre, &end_pre); + if ( !(m->var_ranges[i].mask & MTRR_PHYSMASK_VALID) ) + continue; for ( seg = i + 1; seg < num_var_ranges; seg ++ ) { - phys_base = ((uint64_t*)m->var_ranges)[seg*2]; - phys_mask = ((uint64_t*)m->var_ranges)[seg*2 + 1]; + uint64_t base2 = m->var_ranges[seg].base >> PAGE_SHIFT; + uint64_t mask2 = m->var_ranges[seg].mask >> PAGE_SHIFT; - get_mtrr_range(phys_base, phys_mask, - &base, &end); + if ( !(m->var_ranges[seg].mask & MTRR_PHYSMASK_VALID) ) + continue; - if ( ((base_pre != end_pre) && (base != end)) - || ((base >= base_pre) && (base <= end_pre)) - || ((end >= base_pre) && (end <= end_pre)) - || ((base_pre >= base) && (base_pre <= end)) - || ((end_pre >= base) && (end_pre <= end)) ) + if ( (base1 & mask1 & mask2) == (base2 & mask2 & mask1) ) { /* MTRR is overlapped. */ return 1; @@ -171,8 +136,6 @@ static int __init hvm_mtrr_pat_init(void) } } - size_or_mask = ~((1 << (paddr_bits - PAGE_SHIFT)) - 1); - return 0; } __initcall(hvm_mtrr_pat_init); diff --git a/xen/include/asm-x86/mtrr.h b/xen/include/asm-x86/mtrr.h index 328ba04..7b6515a 100644 --- a/xen/include/asm-x86/mtrr.h +++ b/xen/include/asm-x86/mtrr.h @@ -92,7 +92,7 @@ extern bool_t mtrr_def_type_msr_set(struct domain *, struct mtrr_state *, extern void memory_type_changed(struct domain *); extern bool_t pat_msr_set(uint64_t *pat, uint64_t msr); -bool_t is_var_mtrr_overlapped(struct mtrr_state *m); +bool_t is_var_mtrr_overlapped(const struct mtrr_state *m); bool_t mtrr_pat_not_equal(struct vcpu *vd, struct vcpu *vs); #endif /* __ASM_X86_MTRR_H__ */ -- generated by git-patchbot for /home/xen/git/xen.git#stable-4.5 _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxx http://lists.xensource.com/xen-changelog
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