On Thu, 2015-07-16 at 03:25 +0800, Xiao Guangrong wrote:
> From: Xiao Guangrong <guangrong.x...@intel.com>
>
> Currently code uses default memory type if MTRR is fully disabled,
> fix it by using UC instead
>
> Signed-off-by: Xiao Guangrong <guangrong.x...@intel.com>
> ---
Seems to work for me. I don't see a 0th patch, but for the series:
Tested-by: Alex Williamson <alex.william...@redhat.com>
Thanks!
> arch/x86/kvm/mtrr.c | 21 ++++++++++++++++++++-
> 1 file changed, 20 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/mtrr.c b/arch/x86/kvm/mtrr.c
> index de1d2d8..e275013 100644
> --- a/arch/x86/kvm/mtrr.c
> +++ b/arch/x86/kvm/mtrr.c
> @@ -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;
>
--
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