[PATCH v3 16/20] i386/cpu: Mark cet-u & cet-s xstates as migratable

Zhao Liu posted 20 patches 3 days, 4 hours ago
Maintainers: "Michael S. Tsirkin" <mst@redhat.com>, Cornelia Huck <cohuck@redhat.com>, Paolo Bonzini <pbonzini@redhat.com>, Zhao Liu <zhao1.liu@intel.com>, Marcelo Tosatti <mtosatti@redhat.com>
[PATCH v3 16/20] i386/cpu: Mark cet-u & cet-s xstates as migratable
Posted by Zhao Liu 3 days, 4 hours ago
Cet-u and cet-s are supervisor xstates. Their states are saved/loaded by
saving/loading related CET MSRs. And there's a vmsd "vmstate_cet" to
migrate these MSRs.

Thus, it's safe to mark them as migratable.

Tested-by: Farrah Chen <farrah.chen@intel.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
---
 target/i386/cpu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 0bb65e8c5321..c08066a338a3 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1522,7 +1522,8 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         .migratable_flags = XSTATE_FP_MASK | XSTATE_SSE_MASK |
             XSTATE_YMM_MASK | XSTATE_BNDREGS_MASK | XSTATE_BNDCSR_MASK |
             XSTATE_OPMASK_MASK | XSTATE_ZMM_Hi256_MASK | XSTATE_Hi16_ZMM_MASK |
-            XSTATE_PKRU_MASK | XSTATE_ARCH_LBR_MASK | XSTATE_XTILE_CFG_MASK |
+            XSTATE_PKRU_MASK | XSTATE_CET_U_MASK | XSTATE_CET_S_MASK |
+            XSTATE_ARCH_LBR_MASK | XSTATE_XTILE_CFG_MASK |
             XSTATE_XTILE_DATA_MASK,
     },
     [FEAT_XSAVE_XCR0_HI] = {
-- 
2.34.1
Re: [PATCH v3 16/20] i386/cpu: Mark cet-u & cet-s xstates as migratable
Posted by Zhao Liu 6 minutes ago
On Fri, Oct 24, 2025 at 02:56:28PM +0800, Zhao Liu wrote:
> Date: Fri, 24 Oct 2025 14:56:28 +0800
> From: Zhao Liu <zhao1.liu@intel.com>
> Subject: [PATCH v3 16/20] i386/cpu: Mark cet-u & cet-s xstates as migratable
> X-Mailer: git-send-email 2.34.1
> 
> Cet-u and cet-s are supervisor xstates. Their states are saved/loaded by
> saving/loading related CET MSRs. And there's a vmsd "vmstate_cet" to
> migrate these MSRs.
> 
> Thus, it's safe to mark them as migratable.
> 
> Tested-by: Farrah Chen <farrah.chen@intel.com>
> Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
> ---
>  target/i386/cpu.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 0bb65e8c5321..c08066a338a3 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -1522,7 +1522,8 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
>          .migratable_flags = XSTATE_FP_MASK | XSTATE_SSE_MASK |
>              XSTATE_YMM_MASK | XSTATE_BNDREGS_MASK | XSTATE_BNDCSR_MASK |
>              XSTATE_OPMASK_MASK | XSTATE_ZMM_Hi256_MASK | XSTATE_Hi16_ZMM_MASK |
> -            XSTATE_PKRU_MASK | XSTATE_ARCH_LBR_MASK | XSTATE_XTILE_CFG_MASK |
> +            XSTATE_PKRU_MASK | XSTATE_CET_U_MASK | XSTATE_CET_S_MASK |

CET-U & CET-S should be added to FEAT_XSAVE_XSS_LO.

> +            XSTATE_ARCH_LBR_MASK | XSTATE_XTILE_CFG_MASK |
>              XSTATE_XTILE_DATA_MASK,
>      },
>      [FEAT_XSAVE_XCR0_HI] = {
> -- 
> 2.34.1
>