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KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type

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mtrr_for_each_mem_type() is ready now, use it to simplify
kvm_mtrr_get_guest_memory_type()

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Xiao Guangrong 2015-06-15 16:55:34 +08:00 committed by Paolo Bonzini
parent f571c0973e
commit fa61213746
1 changed files with 16 additions and 48 deletions
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64
arch/x86/kvm/mtrr.c
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@ -600,61 +600,23 @@ static void mtrr_lookup_next(struct mtrr_iter *iter)
u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;
u64 base, mask, start;
int i, num_var_ranges, type;
struct mtrr_iter iter;
u64 start, end;
int type = -1;
const int wt_wb_mask = (1 << MTRR_TYPE_WRBACK)
| (1 << MTRR_TYPE_WRTHROUGH);
start = gfn_to_gpa(gfn);
num_var_ranges = KVM_NR_VAR_MTRR;
type = -1;
end = start + PAGE_SIZE;
/* MTRR is completely disabled, use UC for all of physical memory. */
if (!mtrr_is_enabled(mtrr_state))
return MTRR_TYPE_UNCACHABLE;
/* Look in fixed ranges. Just return the type as per start */
if (fixed_mtrr_is_enabled(mtrr_state) && (start < 0x100000)) {
int idx;
if (start < 0x80000) {
idx = 0;
idx += (start >> 16);
return mtrr_state->fixed_ranges[idx];
} else if (start < 0xC0000) {
idx = 1 * 8;
idx += ((start - 0x80000) >> 14);
return mtrr_state->fixed_ranges[idx];
} else if (start < 0x1000000) {
idx = 3 * 8;
idx += ((start - 0xC0000) >> 12);
return mtrr_state->fixed_ranges[idx];
}
}
/*
* Look in variable ranges
* Look of multiple ranges matching this address and pick type
* as per MTRR precedence
*/
for (i = 0; i < num_var_ranges; ++i) {
int curr_type;
if (!(mtrr_state->var_ranges[i].mask & (1 << 11)))
continue;
base = mtrr_state->var_ranges[i].base & PAGE_MASK;
mask = mtrr_state->var_ranges[i].mask & PAGE_MASK;
if ((start & mask) != (base & mask))
continue;
mtrr_for_each_mem_type(&iter, mtrr_state, start, end) {
int curr_type = iter.mem_type;
/*
* Please refer to Intel SDM Volume 3: 11.11.4.1 MTRR
* Precedences.
*/
curr_type = mtrr_state->var_ranges[i].base & 0xff;
if (type == -1) {
type = curr_type;
continue;
@ -694,9 +656,15 @@ u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
return MTRR_TYPE_WRBACK;
}
if (type != -1)
return type;
return mtrr_default_type(mtrr_state);
/* It is not covered by MTRRs. */
if (iter.partial_map) {
/*
* We just check one page, partially covered by MTRRs is
* impossible.
*/
WARN_ON(type != -1);
type = mtrr_default_type(mtrr_state);
}
return type;
}
EXPORT_SYMBOL_GPL(kvm_mtrr_get_guest_memory_type);