On 20/02/2024 17:27, John Allen wrote: > On Wed, Feb 07, 2024 at 11:21:05AM +0000, Joao Martins wrote: >> On 12/09/2023 22:18, John Allen wrote: >>> In the event that a guest process attempts to access memory that has >>> been poisoned in response to a deferred uncorrected MCE, an AMD system >>> will currently generate a SIGBUS error which will result in the entire >>> guest being shutdown. Ideally, we only want to kill the guest process >>> that accessed poisoned memory in this case. >>> >>> This support has been included in qemu for Intel hosts for a long time, >>> but there are a couple of changes needed for AMD hosts. First, we will >>> need to expose the SUCCOR cpuid bit to guests. Second, we need to modify >>> the MCE injection code to avoid Intel specific behavior when we are >>> running on an AMD host. >>> >> >> Is there any update with respect to this series? >> >> John's series should fix MCE injection on AMD; as today it is just crashing >> the >> guest (sadly) when an MCE happens in the hypervisor. >> >> William, Paolo, I think the sort-of-dependency(?) of this where we block >> migration if there was a poisoned page on is already in Peter's migration >> tree[1] (CC'ed). So perhaps this series just needs John to resend it given >> that >> it's been a couple months since v4? > > It looks like this series still applies cleanly to latest qemu, but I > can resend if needed. > That's great I suppose.
I was hoping Paolo responds, to understand next steps. There's also the other kernel patch that Paolo suggested[0], to declare the SUCCOR bit in the kvm supported CPUID? Maybe it's being held up because of that? [0] https://lore.kernel.org/qemu-devel/d4c1bb9b-8438-ed00-c79d-e8ad2a7e4...@redhat.com/ > Thanks, > John > >> >> [1] >> https://lore.kernel.org/qemu-devel/20240130190640.139364-2-william.ro...@oracle.com/ >> >>> v2: >>> - Add "succor" feature word. >>> - Add case to kvm_arch_get_supported_cpuid for the SUCCOR feature. >>> >>> v3: >>> - Reorder series. Only enable SUCCOR after bugs have been fixed. >>> - Introduce new patch ignoring AO errors. >>> >>> v4: >>> - Remove redundant check for AO errors. >>> >>> John Allen (2): >>> i386: Fix MCE support for AMD hosts >>> i386: Add support for SUCCOR feature >>> >>> William Roche (1): >>> i386: Explicitly ignore unsupported BUS_MCEERR_AO MCE on AMD guest >>> >>> target/i386/cpu.c | 18 +++++++++++++++++- >>> target/i386/cpu.h | 4 ++++ >>> target/i386/helper.c | 4 ++++ >>> target/i386/kvm/kvm.c | 28 ++++++++++++++++++++-------- >>> 4 files changed, 45 insertions(+), 9 deletions(-) >>> >>
