KVM: MTRR: introduce mtrr_for_each_mem_type

It walks all MTRRs and gets all the memory cache type setting for the
specified range also it checks if the range is fully covered by MTRRs

Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
[Adjust for range_size->range_shift change. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Xiao Guangrong 2015-06-15 16:55:33 +08:00 committed by Paolo Bonzini
parent f7bfb57b3e
commit f571c0973e
1 changed files with 188 additions and 0 deletions

View File

@ -220,6 +220,15 @@ static int fixed_mtrr_seg_unit_range_index(int seg, int unit)
return mtrr_seg->range_start + 8 * unit;
}
static int fixed_mtrr_seg_end_range_index(int seg)
{
struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg];
int n;
n = (mtrr_seg->end - mtrr_seg->start) >> mtrr_seg->range_shift;
return mtrr_seg->range_start + n - 1;
}
static bool fixed_msr_to_range(u32 msr, u64 *start, u64 *end)
{
int seg, unit;
@ -266,6 +275,14 @@ static int fixed_mtrr_addr_seg_to_range_index(u64 addr, int seg)
return index;
}
static u64 fixed_mtrr_range_end_addr(int seg, int index)
{
struct fixed_mtrr_segment *mtrr_seg = &fixed_seg_table[seg];
int pos = index - mtrr_seg->range_start;
return mtrr_seg->start + ((pos + 1) << mtrr_seg->range_shift);
}
static void var_mtrr_range(struct kvm_mtrr_range *range, u64 *start, u64 *end)
{
u64 mask;
@ -409,6 +426,177 @@ void kvm_vcpu_mtrr_init(struct kvm_vcpu *vcpu)
INIT_LIST_HEAD(&vcpu->arch.mtrr_state.head);
}
struct mtrr_iter {
/* input fields. */
struct kvm_mtrr *mtrr_state;
u64 start;
u64 end;
/* output fields. */
int mem_type;
/* [start, end) is not fully covered in MTRRs? */
bool partial_map;
/* private fields. */
union {
/* used for fixed MTRRs. */
struct {
int index;
int seg;
};
/* used for var MTRRs. */
struct {
struct kvm_mtrr_range *range;
/* max address has been covered in var MTRRs. */
u64 start_max;
};
};
bool fixed;
};
static bool mtrr_lookup_fixed_start(struct mtrr_iter *iter)
{
int seg, index;
if (!fixed_mtrr_is_enabled(iter->mtrr_state))
return false;
seg = fixed_mtrr_addr_to_seg(iter->start);
if (seg < 0)
return false;
iter->fixed = true;
index = fixed_mtrr_addr_seg_to_range_index(iter->start, seg);
iter->index = index;
iter->seg = seg;
return true;
}
static bool match_var_range(struct mtrr_iter *iter,
struct kvm_mtrr_range *range)
{
u64 start, end;
var_mtrr_range(range, &start, &end);
if (!(start >= iter->end || end <= iter->start)) {
iter->range = range;
/*
* the function is called when we do kvm_mtrr.head walking.
* Range has the minimum base address which interleaves
* [looker->start_max, looker->end).
*/
iter->partial_map |= iter->start_max < start;
/* update the max address has been covered. */
iter->start_max = max(iter->start_max, end);
return true;
}
return false;
}
static void __mtrr_lookup_var_next(struct mtrr_iter *iter)
{
struct kvm_mtrr *mtrr_state = iter->mtrr_state;
list_for_each_entry_continue(iter->range, &mtrr_state->head, node)
if (match_var_range(iter, iter->range))
return;
iter->range = NULL;
iter->partial_map |= iter->start_max < iter->end;
}
static void mtrr_lookup_var_start(struct mtrr_iter *iter)
{
struct kvm_mtrr *mtrr_state = iter->mtrr_state;
iter->fixed = false;
iter->start_max = iter->start;
iter->range = list_prepare_entry(iter->range, &mtrr_state->head, node);
__mtrr_lookup_var_next(iter);
}
static void mtrr_lookup_fixed_next(struct mtrr_iter *iter)
{
/* terminate the lookup. */
if (fixed_mtrr_range_end_addr(iter->seg, iter->index) >= iter->end) {
iter->fixed = false;
iter->range = NULL;
return;
}
iter->index++;
/* have looked up for all fixed MTRRs. */
if (iter->index >= ARRAY_SIZE(iter->mtrr_state->fixed_ranges))
return mtrr_lookup_var_start(iter);
/* switch to next segment. */
if (iter->index > fixed_mtrr_seg_end_range_index(iter->seg))
iter->seg++;
}
static void mtrr_lookup_var_next(struct mtrr_iter *iter)
{
__mtrr_lookup_var_next(iter);
}
static void mtrr_lookup_start(struct mtrr_iter *iter)
{
if (!mtrr_is_enabled(iter->mtrr_state)) {
iter->partial_map = true;
return;
}
if (!mtrr_lookup_fixed_start(iter))
mtrr_lookup_var_start(iter);
}
static void mtrr_lookup_init(struct mtrr_iter *iter,
struct kvm_mtrr *mtrr_state, u64 start, u64 end)
{
iter->mtrr_state = mtrr_state;
iter->start = start;
iter->end = end;
iter->partial_map = false;
iter->fixed = false;
iter->range = NULL;
mtrr_lookup_start(iter);
}
static bool mtrr_lookup_okay(struct mtrr_iter *iter)
{
if (iter->fixed) {
iter->mem_type = iter->mtrr_state->fixed_ranges[iter->index];
return true;
}
if (iter->range) {
iter->mem_type = iter->range->base & 0xff;
return true;
}
return false;
}
static void mtrr_lookup_next(struct mtrr_iter *iter)
{
if (iter->fixed)
mtrr_lookup_fixed_next(iter);
else
mtrr_lookup_var_next(iter);
}
#define mtrr_for_each_mem_type(_iter_, _mtrr_, _gpa_start_, _gpa_end_) \
for (mtrr_lookup_init(_iter_, _mtrr_, _gpa_start_, _gpa_end_); \
mtrr_lookup_okay(_iter_); mtrr_lookup_next(_iter_))
u8 kvm_mtrr_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn)
{
struct kvm_mtrr *mtrr_state = &vcpu->arch.mtrr_state;