Re: [PATCH 1/4] KVM: VMX: read the PML log in the same order as it was written

On Fri, Dec 13, 2024, Maxim Levitsky wrote: > On Thu, 2024-12-12 at 22:19 -0800, Sean Christopherson wrote: > > On Thu, Dec 12, 2024, Maxim Levitsky wrote: > > > On Wed, 2024-12-11 at 16:44 -0800, Sean Christopherson wrote: > > > > But, I can't help but wonder why KVM bothers emulating PML. I can

Re: [PATCH 1/4] KVM: VMX: read the PML log in the same order as it was written

On Thu, 2024-12-12 at 22:19 -0800, Sean Christopherson wrote: > On Thu, Dec 12, 2024, Maxim Levitsky wrote: > > On Wed, 2024-12-11 at 16:44 -0800, Sean Christopherson wrote: > > > But, I can't help but wonder why KVM bothers emulating PML. I can > > > appreciate > > > that avoiding exits to L1 wo

Re: [PATCH 1/4] KVM: VMX: read the PML log in the same order as it was written

On Thu, Dec 12, 2024, Maxim Levitsky wrote: > On Wed, 2024-12-11 at 16:44 -0800, Sean Christopherson wrote: > > But, I can't help but wonder why KVM bothers emulating PML. I can > > appreciate > > that avoiding exits to L1 would be beneficial, but what use case actually > > cares > > about dirty

Re: [PATCH 1/4] KVM: VMX: read the PML log in the same order as it was written

On Wed, 2024-12-11 at 16:44 -0800, Sean Christopherson wrote: > On Wed, Dec 11, 2024, Maxim Levitsky wrote: > > X86 spec specifies that the CPU writes to the PML log 'backwards' > > SDM, because this is Intel specific. True. > > > or in other words, it first writes entry 511, then entry 510 and s

Re: [PATCH 1/4] KVM: VMX: read the PML log in the same order as it was written

On Wed, Dec 11, 2024, Maxim Levitsky wrote: > X86 spec specifies that the CPU writes to the PML log 'backwards' SDM, because this is Intel specific. > or in other words, it first writes entry 511, then entry 510 and so on, > until it writes entry 0, after which the 'PML log full' VM exit happens.