On Mon, Oct 15, 2018 at 12:47:25PM +0800, Robert Hoo wrote:
> Note RSBA is specially treated -- no matter host support it or not, qemu
> pretends it is supported.
>
> Signed-off-by: Robert Hoo <robert...@linux.intel.com>
I am now wondering what else we need to be able to remove
CPUID_7_0_EDX_ARCH_CAPABILITIES from
feature_word_info[FEAT_7_0_EDX].unmigratable_flags.
This series is necessary for that, be I think we still can't let
the VM be migrated if arch-capabilities is enabled and we're
running on a host that doesn't have MSR_IA32_ARCH_CAPABILITIES on
kvm_feature_msrs.
Reviewed-by: Eduardo Habkost <ehabk...@redhat.com>
> ---
> target/i386/cpu.c | 31 ++++++++++++++++++++++++++++++-
> target/i386/cpu.h | 8 ++++++++
> target/i386/kvm.c | 11 +++++++++++
> 3 files changed, 49 insertions(+), 1 deletion(-)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index d191b9c..51c8fd8 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -1141,6 +1141,27 @@ static FeatureWordInfo
> feature_word_info[FEATURE_WORDS] = {
> },
> .tcg_features = ~0U,
> },
> + /*Below are MSR exposed features*/
> + [FEAT_ARCH_CAPABILITIES] = {
> + .type = MSR_FEATURE_WORD,
> + .feat_names = {
> + "rdctl-no", "ibrs-all", "rsba", "skip-l1dfl-vmentry",
> + "ssb-no", NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + NULL, NULL, NULL, NULL,
> + },
> + .msr = {
> + .index = MSR_IA32_ARCH_CAPABILITIES,
> + .cpuid_dep = {
> + FEAT_7_0_EDX,
> + CPUID_7_0_EDX_ARCH_CAPABILITIES
> + }
> + },
> + },
> };
>
> typedef struct X86RegisterInfo32 {
> @@ -3696,7 +3717,15 @@ static uint32_t
> x86_cpu_get_supported_feature_word(FeatureWord w,
> wi->cpuid.reg);
> break;
> case MSR_FEATURE_WORD:
> - r = kvm_arch_get_supported_msr_feature(kvm_state, wi->msr.index);
> + /* Special case:
> + * No matter host status, IA32_ARCH_CAPABILITIES.RSBA [bit 2]
> + * is always supported in guest.
> + */
> + if (wi->msr.index == MSR_IA32_ARCH_CAPABILITIES) {
> + r = MSR_ARCH_CAP_RSBA;
> + }
> + r |= kvm_arch_get_supported_msr_feature(kvm_state,
> + wi->msr.index);
> break;
> }
> } else if (hvf_enabled()) {
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 730c06f..52a52ec 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -502,6 +502,7 @@ typedef enum FeatureWord {
> FEAT_6_EAX, /* CPUID[6].EAX */
> FEAT_XSAVE_COMP_LO, /* CPUID[EAX=0xd,ECX=0].EAX */
> FEAT_XSAVE_COMP_HI, /* CPUID[EAX=0xd,ECX=0].EDX */
> + FEAT_ARCH_CAPABILITIES,
> FEATURE_WORDS,
> } FeatureWord;
>
> @@ -730,6 +731,13 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
> #define CPUID_TOPOLOGY_LEVEL_SMT (1U << 8)
> #define CPUID_TOPOLOGY_LEVEL_CORE (2U << 8)
>
> +/* MSR Feature Bits */
> +#define MSR_ARCH_CAP_RDCL_NO (1U << 0)
> +#define MSR_ARCH_CAP_IBRS_ALL (1U << 1)
> +#define MSR_ARCH_CAP_RSBA (1U << 2)
> +#define MSR_ARCH_CAP_SKIP_L1DFL_VMENTRY (1U << 3)
> +#define MSR_ARCH_CAP_SSB_NO (1U << 4)
> +
> #ifndef HYPERV_SPINLOCK_NEVER_RETRY
> #define HYPERV_SPINLOCK_NEVER_RETRY 0xFFFFFFFF
> #endif
> diff --git a/target/i386/kvm.c b/target/i386/kvm.c
> index db79dad..2f7b40d 100644
> --- a/target/i386/kvm.c
> +++ b/target/i386/kvm.c
> @@ -1928,6 +1928,17 @@ static int kvm_put_msrs(X86CPU *cpu, int level)
> }
> #endif
>
> + /* If host supports feature MSR, write down. */
> + if (kvm_feature_msrs) {
> + int i;
> + for (i = 0; i < kvm_feature_msrs->nmsrs; i++)
> + if (kvm_feature_msrs->indices[i] == MSR_IA32_ARCH_CAPABILITIES) {
> + kvm_msr_entry_add(cpu, MSR_IA32_ARCH_CAPABILITIES,
> + env->features[FEAT_ARCH_CAPABILITIES]);
> + break;
> + }
> + }
> +
> /*
> * The following MSRs have side effects on the guest or are too heavy
> * for normal writeback. Limit them to reset or full state updates.
> --
> 1.8.3.1
>
>
--
Eduardo
