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Subject[PATCH 13/15] KVM: MTRR: simplify kvm_mtrr_get_guest_memory_type
Date
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>
---
arch/x86/kvm/mtrr.c | 61 +++++++++++++----------------------------------------
1 file changed, 15 insertions(+), 46 deletions(-)

diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
index 35f86303..bc90834 100644
--- a/arch/x86/kvm/mtrr.c
+++ b/arch/x86/kvm/mtrr.c
@@ -581,56 +581,19 @@ static void mtrr_lookup_next(struct mtrr_looker *looker)
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 = gfn_to_gpa(gfn);
- int i, num_var_ranges = KVM_NR_VAR_MTRR, type_mask, type = -1;
-
- /* MTRR is completely disabled, use UC for all of physical memory. */
- if (!mtrr_state->mtrr_enabled)
- return MTRR_TYPE_UNCACHABLE;
-
- /* Look in fixed ranges. Just return the type as per start */
- if (mtrr_state->fixed_mtrr_enabled && (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];
- }
- }
+ struct mtrr_looker looker;
+ u64 start = gfn_to_gpa(gfn), end = start + PAGE_SIZE;
+ int type_mask, type = -1;

- /*
- * Look in variable ranges
- * Look of multiple ranges matching this address and pick type
- * as per MTRR precedence
- */
type_mask = (1 << MTRR_TYPE_WRBACK) | (1 << MTRR_TYPE_WRTHROUGH);
- 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(&looker, mtrr_state, start, end) {
+ int curr_type = looker.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;
@@ -670,9 +633,15 @@ 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_state->def_type;
+ /* It is not covered by MTRRs. */
+ if (looker.partial_map) {
+ /*
+ * We just check one page, partially covered by MTRRs is
+ * impossible.
+ */
+ WARN_ON(type != -1);
+ type = mtrr_state->def_type;
+ }
+ return type;
}
EXPORT_SYMBOL_GPL(kvm_mtrr_get_guest_memory_type);
--
2.1.0


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