* [PATCH] i386: Add CPUID bit for CLZERO and XSAVEERPTR
@ 2019-09-25 21:49 Sebastian Andrzej Siewior
2019-09-26 11:05 ` Paolo Bonzini
2019-09-26 11:06 ` Paolo Bonzini
0 siblings, 2 replies; 4+ messages in thread
From: Sebastian Andrzej Siewior @ 2019-09-25 21:49 UTC (permalink / raw)
To: qemu-devel
Cc: Paolo Bonzini, Sebastian Andrzej Siewior, Eduardo Habkost,
Richard Henderson
The CPUID bits CLZERO and XSAVEERPTR are availble on AMD's ZEN platform
and could be passed to the guest.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
I tweaked the kernel to expose these flags and figured out that this is
also missing in order see those bits in the guest.
target/i386/cpu.c | 2 +-
target/i386/cpu.h | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index fbed2eb804e32..e00ef3c917391 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -1113,7 +1113,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
[FEAT_8000_0008_EBX] = {
.type = CPUID_FEATURE_WORD,
.feat_names = {
- NULL, NULL, NULL, NULL,
+ "clzero", NULL, "xsaveerptr", NULL,
NULL, NULL, NULL, NULL,
NULL, "wbnoinvd", NULL, NULL,
"ibpb", NULL, NULL, NULL,
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 0732e059ec989..cc475c703fc4d 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -689,6 +689,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
#define CPUID_7_0_EDX_ARCH_CAPABILITIES (1U << 29) /*Arch Capabilities*/
#define CPUID_7_0_EDX_SPEC_CTRL_SSBD (1U << 31) /* Speculative Store Bypass Disable */
+#define CPUD_800_008_EBX_CLZERO (1U << 0) /* CLZERO instruction */
+#define CPUD_800_008_EBX_XSAVEERPTR (1U << 2) /* Always save/restore FP error pointers */
#define CPUID_8000_0008_EBX_WBNOINVD (1U << 9) /* Write back and
do not invalidate cache */
#define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch Prediction Barrier */
--
2.23.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] i386: Add CPUID bit for CLZERO and XSAVEERPTR
2019-09-25 21:49 [PATCH] i386: Add CPUID bit for CLZERO and XSAVEERPTR Sebastian Andrzej Siewior
@ 2019-09-26 11:05 ` Paolo Bonzini
2019-09-26 11:06 ` Paolo Bonzini
1 sibling, 0 replies; 4+ messages in thread
From: Paolo Bonzini @ 2019-09-26 11:05 UTC (permalink / raw)
To: Sebastian Andrzej Siewior, qemu-devel; +Cc: Eduardo Habkost, Richard Henderson
On 25/09/19 23:49, Sebastian Andrzej Siewior wrote:
> The CPUID bits CLZERO and XSAVEERPTR are availble on AMD's ZEN platform
> and could be passed to the guest.
>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>
> I tweaked the kernel to expose these flags and figured out that this is
> also missing in order see those bits in the guest.
>
> target/i386/cpu.c | 2 +-
> target/i386/cpu.h | 2 ++
> 2 files changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index fbed2eb804e32..e00ef3c917391 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -1113,7 +1113,7 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
> [FEAT_8000_0008_EBX] = {
> .type = CPUID_FEATURE_WORD,
> .feat_names = {
> - NULL, NULL, NULL, NULL,
> + "clzero", NULL, "xsaveerptr", NULL,
> NULL, NULL, NULL, NULL,
> NULL, "wbnoinvd", NULL, NULL,
> "ibpb", NULL, NULL, NULL,
> diff --git a/target/i386/cpu.h b/target/i386/cpu.h
> index 0732e059ec989..cc475c703fc4d 100644
> --- a/target/i386/cpu.h
> +++ b/target/i386/cpu.h
> @@ -689,6 +689,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS];
> #define CPUID_7_0_EDX_ARCH_CAPABILITIES (1U << 29) /*Arch Capabilities*/
> #define CPUID_7_0_EDX_SPEC_CTRL_SSBD (1U << 31) /* Speculative Store Bypass Disable */
>
> +#define CPUD_800_008_EBX_CLZERO (1U << 0) /* CLZERO instruction */
> +#define CPUD_800_008_EBX_XSAVEERPTR (1U << 2) /* Always save/restore FP error pointers */
> #define CPUID_8000_0008_EBX_WBNOINVD (1U << 9) /* Write back and
> do not invalidate cache */
> #define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch Prediction Barrier */
>
Yup, queued this one.
Paolo
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] i386: Add CPUID bit for CLZERO and XSAVEERPTR
2019-09-25 21:49 [PATCH] i386: Add CPUID bit for CLZERO and XSAVEERPTR Sebastian Andrzej Siewior
2019-09-26 11:05 ` Paolo Bonzini
@ 2019-09-26 11:06 ` Paolo Bonzini
2019-09-26 11:21 ` Sebastian Andrzej Siewior
1 sibling, 1 reply; 4+ messages in thread
From: Paolo Bonzini @ 2019-09-26 11:06 UTC (permalink / raw)
To: Sebastian Andrzej Siewior, qemu-devel; +Cc: Eduardo Habkost, Richard Henderson
On 25/09/19 23:49, Sebastian Andrzej Siewior wrote:
> #define CPUID_7_0_EDX_SPEC_CTRL_SSBD (1U << 31) /* Speculative Store Bypass Disable */
>
> +#define CPUD_800_008_EBX_CLZERO (1U << 0) /* CLZERO instruction */
> +#define CPUD_800_008_EBX_XSAVEERPTR (1U << 2) /* Always save/restore FP error pointers */
> #define CPUID_8000_0008_EBX_WBNOINVD (1U << 9) /* Write back and
Well, there are obvious typos here but I can fix them for you.
Which processors have these?
Paolo
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] i386: Add CPUID bit for CLZERO and XSAVEERPTR
2019-09-26 11:06 ` Paolo Bonzini
@ 2019-09-26 11:21 ` Sebastian Andrzej Siewior
0 siblings, 0 replies; 4+ messages in thread
From: Sebastian Andrzej Siewior @ 2019-09-26 11:21 UTC (permalink / raw)
To: Paolo Bonzini; +Cc: qemu-devel, Eduardo Habkost, Richard Henderson
On 2019-09-26 13:06:34 [+0200], Paolo Bonzini wrote:
> On 25/09/19 23:49, Sebastian Andrzej Siewior wrote:
> > #define CPUID_7_0_EDX_SPEC_CTRL_SSBD (1U << 31) /* Speculative Store Bypass Disable */
> >
> > +#define CPUD_800_008_EBX_CLZERO (1U << 0) /* CLZERO instruction */
> > +#define CPUD_800_008_EBX_XSAVEERPTR (1U << 2) /* Always save/restore FP error pointers */
> > #define CPUID_8000_0008_EBX_WBNOINVD (1U << 9) /* Write back and
>
> Well, there are obvious typos here but I can fix them for you.
Sorry for the missing I.
> Which processors have these?
There are mention in AMD document [0]. I *think* there were introduced
in Zen, see them on a Ryzen and Epyc.
[0] https://www.amd.com/system/files/TechDocs/24594.pdf
> Paolo
Sebastian
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-09-26 11:24 UTC | newest]
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2019-09-25 21:49 [PATCH] i386: Add CPUID bit for CLZERO and XSAVEERPTR Sebastian Andrzej Siewior
2019-09-26 11:05 ` Paolo Bonzini
2019-09-26 11:06 ` Paolo Bonzini
2019-09-26 11:21 ` Sebastian Andrzej Siewior
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