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authorXiao Guangrong <guangrong.xiao@linux.intel.com>2015-05-13 09:42:19 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2015-05-19 21:52:42 +0300
commitd69afbc6b1b5d0579f13d1a6339d952c4f60a9f4 (patch)
tree6b277abdcd5c8801a1c29c849cda0011e9b77c9b /arch/x86/kvm/mmu.c
parent6a49f85c7ac83c1918d138d40492a5cef40b5ff8 (diff)
downloadlinux-d69afbc6b1b5d0579f13d1a6339d952c4f60a9f4.tar.xz
KVM: MMU: fix decoding cache type from MTRR
There are some bugs in current get_mtrr_type(); 1: bit 1 of mtrr_state->enabled is corresponding bit 11 of IA32_MTRR_DEF_TYPE MSR which completely control MTRR's enablement that means other bits are ignored if it is cleared 2: the fixed MTRR ranges are controlled by bit 0 of mtrr_state->enabled (bit 10 of IA32_MTRR_DEF_TYPE) 3: if MTRR is disabled, UC is applied to all of physical memory rather than mtrr_state->def_type Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Reviewed-by: Wanpeng Li <wanpeng.li@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.c')
-rw-r--r--arch/x86/kvm/mmu.c14
1 files changed, 6 insertions, 8 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index ddf25f39735a..e718c76609f9 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -2431,19 +2431,20 @@ EXPORT_SYMBOL_GPL(kvm_mmu_unprotect_page);
static int get_mtrr_type(struct mtrr_state_type *mtrr_state,
u64 start, u64 end)
{
- int i;
u64 base, mask;
u8 prev_match, curr_match;
- int num_var_ranges = KVM_NR_VAR_MTRR;
+ int i, num_var_ranges = KVM_NR_VAR_MTRR;
- if (!mtrr_state->enabled)
- return 0xFF;
+ /* MTRR is completely disabled, use UC for all of physical memory. */
+ if (!(mtrr_state->enabled & 0x2))
+ return MTRR_TYPE_UNCACHABLE;
/* Make end inclusive end, instead of exclusive */
end--;
/* Look in fixed ranges. Just return the type as per start */
- if (mtrr_state->have_fixed && (start < 0x100000)) {
+ if (mtrr_state->have_fixed && (mtrr_state->enabled & 0x1) &&
+ (start < 0x100000)) {
int idx;
if (start < 0x80000) {
@@ -2466,9 +2467,6 @@ static int get_mtrr_type(struct mtrr_state_type *mtrr_state,
* Look of multiple ranges matching this address and pick type
* as per MTRR precedence
*/
- if (!(mtrr_state->enabled & 2))
- return mtrr_state->def_type;
-
prev_match = 0xFF;
for (i = 0; i < num_var_ranges; ++i) {
unsigned short start_state, end_state;