* [Qemu-devel] [PATCH] i386: Fix nested SVM on older Opterons
@ 2019-05-16 12:58 Bernhard M. Wiedemann
2019-05-23 18:57 ` Dr. David Alan Gilbert
0 siblings, 1 reply; 5+ messages in thread
From: Bernhard M. Wiedemann @ 2019-05-16 12:58 UTC (permalink / raw)
To: qemu-devel; +Cc: Bernhard M. Wiedemann
Without this patch, a VM on a Opteron G3 host will have the svm flag, but
the kvm-amd module fails to load in there, complaining that it needs
cpuid 0x8000000a
I have successfully built and tested this for 3+ years in production
on Opteron G3 servers.
Signed-off-by: Bernhard M. Wiedemann <bwiedemann@suse.de>
---
target/i386/cpu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 722c5514d4..df1d81ded8 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -2723,7 +2723,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
CPUID_EXT_SSE3,
.features[FEAT_8000_0001_EDX] =
CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL,
- .xlevel = 0x80000008,
+ .xlevel = 0x8000000A,
.model_id = "AMD Opteron 240 (Gen 1 Class Opteron)",
},
{
@@ -2745,7 +2745,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL,
.features[FEAT_8000_0001_ECX] =
CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
- .xlevel = 0x80000008,
+ .xlevel = 0x8000000A,
.model_id = "AMD Opteron 22xx (Gen 2 Class Opteron)",
},
{
@@ -2770,7 +2770,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
.features[FEAT_8000_0001_ECX] =
CPUID_EXT3_MISALIGNSSE | CPUID_EXT3_SSE4A |
CPUID_EXT3_ABM | CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
- .xlevel = 0x80000008,
+ .xlevel = 0x8000000A,
.model_id = "AMD Opteron 23xx (Gen 3 Class Opteron)",
},
{
--
2.16.4
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [PATCH] i386: Fix nested SVM on older Opterons
2019-05-16 12:58 [Qemu-devel] [PATCH] i386: Fix nested SVM on older Opterons Bernhard M. Wiedemann
@ 2019-05-23 18:57 ` Dr. David Alan Gilbert
2019-05-23 21:27 ` Eduardo Habkost
0 siblings, 1 reply; 5+ messages in thread
From: Dr. David Alan Gilbert @ 2019-05-23 18:57 UTC (permalink / raw)
To: Bernhard M. Wiedemann, ehabkost, bsd; +Cc: qemu-devel
* Bernhard M. Wiedemann (bwiedemann@suse.de) wrote:
> Without this patch, a VM on a Opteron G3 host will have the svm flag, but
> the kvm-amd module fails to load in there, complaining that it needs
> cpuid 0x8000000a
>
> I have successfully built and tested this for 3+ years in production
> on Opteron G3 servers.
>
> Signed-off-by: Bernhard M. Wiedemann <bwiedemann@suse.de>
> ---
> target/i386/cpu.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 722c5514d4..df1d81ded8 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -2723,7 +2723,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
> CPUID_EXT_SSE3,
> .features[FEAT_8000_0001_EDX] =
> CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL,
> - .xlevel = 0x80000008,
> + .xlevel = 0x8000000A,
> .model_id = "AMD Opteron 240 (Gen 1 Class Opteron)",
> },
> {
> @@ -2745,7 +2745,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
> CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL,
> .features[FEAT_8000_0001_ECX] =
> CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
> - .xlevel = 0x80000008,
> + .xlevel = 0x8000000A,
> .model_id = "AMD Opteron 22xx (Gen 2 Class Opteron)",
> },
> {
> @@ -2770,7 +2770,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
> .features[FEAT_8000_0001_ECX] =
> CPUID_EXT3_MISALIGNSSE | CPUID_EXT3_SSE4A |
> CPUID_EXT3_ABM | CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
> - .xlevel = 0x80000008,
> + .xlevel = 0x8000000A,
> .model_id = "AMD Opteron 23xx (Gen 3 Class Opteron)",
> },
> {
cc'ing in Bandan and Eduardo,
I suspect these need to have compatibility entries on the machine types
so that old machine types don't notice the improvement.
Dave
> --
> 2.16.4
>
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [PATCH] i386: Fix nested SVM on older Opterons
2019-05-23 18:57 ` Dr. David Alan Gilbert
@ 2019-05-23 21:27 ` Eduardo Habkost
2019-05-27 7:49 ` Bernhard M. Wiedemann
0 siblings, 1 reply; 5+ messages in thread
From: Eduardo Habkost @ 2019-05-23 21:27 UTC (permalink / raw)
To: Dr. David Alan Gilbert; +Cc: Bernhard M. Wiedemann, bsd, qemu-devel
On Thu, May 23, 2019 at 07:57:38PM +0100, Dr. David Alan Gilbert wrote:
> * Bernhard M. Wiedemann (bwiedemann@suse.de) wrote:
> > Without this patch, a VM on a Opteron G3 host will have the svm flag, but
> > the kvm-amd module fails to load in there, complaining that it needs
> > cpuid 0x8000000a
> >
> > I have successfully built and tested this for 3+ years in production
> > on Opteron G3 servers.
Have you reproduced the bug on QEMU 2.8 or newer? The problem
you describe should be fixed by the following commit (from ~2.5
years ago).
commit 0c3d7c0051576d220e6da0a8ac08f2d8482e2f0b
Author: Eduardo Habkost <ehabkost@redhat.com>
Date: Wed Sep 21 15:01:35 2016 -0300
target-i386: Enable CPUID[0x8000000A] if SVM is enabled
SVM needs CPUID[0x8000000A] to be available. So if SVM is enabled
in a CPU model or explicitly in the command-line, adjust CPUID
xlevel to expose the CPUID[0x8000000A] leaf.
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
--
Eduardo
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [PATCH] i386: Fix nested SVM on older Opterons
2019-05-23 21:27 ` Eduardo Habkost
@ 2019-05-27 7:49 ` Bernhard M. Wiedemann
0 siblings, 0 replies; 5+ messages in thread
From: Bernhard M. Wiedemann @ 2019-05-27 7:49 UTC (permalink / raw)
To: Eduardo Habkost, Dr. David Alan Gilbert; +Cc: bsd, qemu-devel
On 23/05/2019 23.27, Eduardo Habkost wrote:
> On Thu, May 23, 2019 at 07:57:38PM +0100, Dr. David Alan Gilbert wrote:
>> * Bernhard M. Wiedemann (bwiedemann@suse.de) wrote:
>>> Without this patch, a VM on a Opteron G3 host will have the svm flag, but
>>> the kvm-amd module fails to load in there, complaining that it needs
>>> cpuid 0x8000000a
>>>
>>> I have successfully built and tested this for 3+ years in production
>>> on Opteron G3 servers.
>
> Have you reproduced the bug on QEMU 2.8 or newer? The problem
> you describe should be fixed by the following commit (from ~2.5
> years ago).
>
> commit 0c3d7c0051576d220e6da0a8ac08f2d8482e2f0b
> target-i386: Enable CPUID[0x8000000A] if SVM is enabled
I was still on qemu-2.6.2 so it is good to know that this might work out
of the box with 2.8+
Thanks for the pointer.
^ permalink raw reply [flat|nested] 5+ messages in thread
* [Qemu-devel] [PATCH] i386: Fix nested SVM on older Opterons
@ 2019-05-16 14:38 Bernhard M. Wiedemann
0 siblings, 0 replies; 5+ messages in thread
From: Bernhard M. Wiedemann @ 2019-05-16 14:38 UTC (permalink / raw)
To: qemu-devel; +Cc: Bernhard M. Wiedemann
Without this patch, a VM on a Opteron G3 host will have the svm flag, but
the kvm-amd module fails to load in there, complaining that it needs
cpuid 0x8000000a
I have successfully built and tested this for 3+ years in production
on Opteron G3 servers.
Signed-off-by: Bernhard M. Wiedemann <bwiedemann@suse.de>
---
target/i386/cpu.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 722c5514d4..df1d81ded8 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -2723,7 +2723,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
CPUID_EXT_SSE3,
.features[FEAT_8000_0001_EDX] =
CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL,
- .xlevel = 0x80000008,
+ .xlevel = 0x8000000A,
.model_id = "AMD Opteron 240 (Gen 1 Class Opteron)",
},
{
@@ -2745,7 +2745,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
CPUID_EXT2_LM | CPUID_EXT2_NX | CPUID_EXT2_SYSCALL,
.features[FEAT_8000_0001_ECX] =
CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
- .xlevel = 0x80000008,
+ .xlevel = 0x8000000A,
.model_id = "AMD Opteron 22xx (Gen 2 Class Opteron)",
},
{
@@ -2770,7 +2770,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
.features[FEAT_8000_0001_ECX] =
CPUID_EXT3_MISALIGNSSE | CPUID_EXT3_SSE4A |
CPUID_EXT3_ABM | CPUID_EXT3_SVM | CPUID_EXT3_LAHF_LM,
- .xlevel = 0x80000008,
+ .xlevel = 0x8000000A,
.model_id = "AMD Opteron 23xx (Gen 3 Class Opteron)",
},
{
--
2.16.4
^ permalink raw reply related [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-05-27 7:50 UTC | newest]
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2019-05-16 12:58 [Qemu-devel] [PATCH] i386: Fix nested SVM on older Opterons Bernhard M. Wiedemann
2019-05-23 18:57 ` Dr. David Alan Gilbert
2019-05-23 21:27 ` Eduardo Habkost
2019-05-27 7:49 ` Bernhard M. Wiedemann
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2019-05-16 14:38 Bernhard M. Wiedemann
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