leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

KVM: MTRR: fix memory type handling if MTRR is completely disabled

Browse Source 
Currently code uses default memory type if MTRR is fully disabled,
fix it by using UC instead.

Signed-off-by: Xiao Guangrong <guangrong.xiao@intel.com>
Tested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Xiao Guangrong 2015-07-16 03:25:54 +08:00 committed by Paolo Bonzini
parent c5dfd654d0
commit 10dc331ff5
1 changed files with 20 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

21
arch/x86/kvm/mtrr.c
View File

@ -120,6 +120,16 @@ static u8 mtrr_default_type(struct kvm_mtrr *mtrr_state)
return mtrr_state->deftype & IA32_MTRR_DEF_TYPE_TYPE_MASK;
}
static u8 mtrr_disabled_type(void)
{
/*
* Intel SDM 11.11.2.2: all MTRRs are disabled when
* IA32_MTRR_DEF_TYPE.E bit is cleared, and the UC
* memory type is applied to all of physical memory.
*/
return MTRR_TYPE_UNCACHABLE;
}
/*
* Three terms are used in the following code:
* - segment, it indicates the address segments covered by fixed MTRRs.
@ -434,6 +444,8 @@ struct mtrr_iter {
/* output fields. */
int mem_type;
/* mtrr is completely disabled? */
bool mtrr_disabled;
/* [start, end) is not fully covered in MTRRs? */
bool partial_map;
@ -549,7 +561,7 @@ static void mtrr_lookup_var_next(struct mtrr_iter *iter)
static void mtrr_lookup_start(struct mtrr_iter *iter)
{
if (!mtrr_is_enabled(iter->mtrr_state)) {
iter->partial_map = true;
iter->mtrr_disabled = true;
return;
}
@ -563,6 +575,7 @@ static void mtrr_lookup_init(struct mtrr_iter *iter,
iter->mtrr_state = mtrr_state;
iter->start = start;
iter->end = end;
iter->mtrr_disabled = false;
iter->partial_map = false;
iter->fixed = false;
iter->range = NULL;
@ -656,6 +669,9 @@ u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
return MTRR_TYPE_WRBACK;
}
if (iter.mtrr_disabled)
return mtrr_disabled_type();
/* It is not covered by MTRRs. */
if (iter.partial_map) {
/*
@ -689,6 +705,9 @@ bool kvm_mtrr_check_gfn_range_consistency(struct kvm_vcpu *vcpu, gfn_t gfn,
return false;
}
if (iter.mtrr_disabled)
return true;
if (!iter.partial_map)
return true;