> From: Zhong, Yang <yang.zh...@intel.com>
> Sent: Friday, January 7, 2022 5:32 PM
>
> From: Jing Liu <jing2....@intel.com>
>
> Intel introduces XFD faulting mechanism for extended
> XSAVE features to dynamically enable the features in
> runtime. If CPUID (EAX=0Dh, ECX=n, n>1).ECX[2] is set
> as 1, it indicates support for XFD faulting of this
> state component.
>
> Signed-off-by: Jing Liu <jing2....@intel.com>
> Signed-off-by: Yang Zhong <yang.zh...@intel.com>
> ---
> target/i386/cpu.h | 2 +-
> target/i386/cpu.c | 2 +-
> target/i386/kvm/kvm-cpu.c | 1 +
> 3 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 79023fe723..22f7ff40a6 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -1375,7 +1375,7 @@
> QEMU_BUILD_BUG_ON(sizeof(XSaveXTILE_DATA) != 0x2000);
> typedef struct ExtSaveArea {
> uint32_t feature, bits;
> uint32_t offset, size;
> - uint32_t need_align;
> + uint32_t need_align, support_xfd;
why each flag be a 32-bit field?
also it's more natural to have them in separate lines, though I'm not
sure why existing fields are put this way (possibly due to short names?).
> } ExtSaveArea;
>
> #define XSAVE_STATE_AREA_COUNT (XSTATE_XTILE_DATA_BIT + 1)
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index dd2c919c33..1adc3f0f99 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -5495,7 +5495,7 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t
> index, uint32_t count,
> const ExtSaveArea *esa = &x86_ext_save_areas[count];
> *eax = esa->size;
> *ebx = esa->offset;
> - *ecx = esa->need_align << 1;
> + *ecx = (esa->need_align << 1) | (esa->support_xfd << 2);
> }
> }
> break;
> diff --git a/target/i386/kvm/kvm-cpu.c b/target/i386/kvm/kvm-cpu.c
> index 6c4c1c6f9d..3b3c203f11 100644
> --- a/target/i386/kvm/kvm-cpu.c
> +++ b/target/i386/kvm/kvm-cpu.c
> @@ -108,6 +108,7 @@ static void kvm_cpu_xsave_init(void)
>
> uint32_t ecx = kvm_arch_get_supported_cpuid(s, 0xd, i, R_ECX);
> esa->need_align = ecx & (1u << 1) ? 1 : 0;
> + esa->support_xfd = ecx & (1u << 2) ? 1 : 0;
> }
> }
> }
