Re: [PATCH V4 09/11] KVM: x86: Disable Intel Processor Trace when VMXON in L1 guest

From: Paolo Bonzini
Date: Tue Jan 09 2018 - 16:40:04 EST


On 09/01/2018 21:16, Jim Mattson wrote:
> This doesn't look right to me. pt_disable_intercept_for_msr calls
> eitherÂvmx_disable_intercept_for_msr orÂvmx_enable_intercept_for_msr,
> both of which only changeÂvmx_msr_bitmap_legacy
> andÂvmx_msr_bitmap_longmode. Neither of these MSR permission bitmaps is
> likely to be the one in use by L1 (which is more likely to be using the
> mode-appropriate x2apic or x2apic_apicv bitmap). Moreover, these changes
> affect all of the VMs that are using those MSR permission bitmaps.

Yeah, I replied this morning with something like this, on the thread
about removing the longmode bitmaps.

Paolo