From: Paolo Bonzini <pbonzini@redhat.com>
To: John Allen <john.allen@amd.com>, qemu-devel@nongnu.org
Cc: yazen.ghannam@amd.com, michael.roth@amd.com, babu.moger@amd.com,
william.roche@oracle.com, joao.m.martins@oracle.com
Subject: Re: [PATCH 1/2] i386: Add support for SUCCOR feature
Date: Fri, 7 Jul 2023 16:25:22 +0200 [thread overview]
Message-ID: <d4c1bb9b-8438-ed00-c79d-e8ad2a7e4eed@redhat.com> (raw)
In-Reply-To: <20230706194022.2485195-2-john.allen@amd.com>
On 7/6/23 21:40, John Allen wrote:
> case 0x80000007:
> *eax = 0;
> - *ebx = 0;
> + *ebx = env->features[FEAT_8000_0007_EBX] | CPUID_8000_0007_EBX_SUCCOR;
> *ecx = 0;
> *edx = env->features[FEAT_8000_0007_EDX];
> break;
I agree that it needs no hypervisor support, but Babu is right that you
cannot add it unconditionally (especially not on Intel processors).
You can special case CPUID_8000_0007_EBX_SUCCOR in
kvm_arch_get_supported_cpuid() so that it is added even on old kernels.
There are already several such cases. Adding it to KVM is nice to have
anyway, so please send a patch for that.
Also, the patch does not compile (probably you missed a prerequisite) as
it lacks all the rigamarole that is needed to add FEAT_8000_0007_EBX.
Paolo
next prev parent reply other threads:[~2023-07-07 14:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-06 19:40 [PATCH 0/2] Fix MCE handling on AMD hosts John Allen
2023-07-06 19:40 ` [PATCH 1/2] i386: Add support for SUCCOR feature John Allen
2023-07-06 20:22 ` Moger, Babu
2023-07-06 21:07 ` Joao Martins
2023-07-07 14:25 ` Paolo Bonzini [this message]
2023-07-12 19:11 ` John Allen
2023-07-20 13:29 ` Joao Martins
2023-07-06 19:40 ` [PATCH 2/2] i386: Fix MCE support for AMD hosts John Allen
2023-07-06 21:07 ` Joao Martins
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