Re: [Xen-devel] [PATCH V5] x86/hvm: fix domain crash when CR3 has the noflush bit set

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 16.02.18 at 11:22, <rcojocaru@xxxxxxxxxxxxxxx> wrote:
> The emulation layers of Xen lack PCID support, and as we only offer
> PCID to HAP guests, all writes to CR3 are handled by hardware,
> except when introspection is involved. Consequently, trying to set
> CR3 when the noflush bit is set in hvm_set_cr3() leads to domain
> crashes. The workaround is to clear the noflush bit in
> hvm_set_cr3(). CR3 values in hvm_monitor_cr() are also sanitized.
> Additionally, a bool parameter now propagates to
> {svm,vmx}_update_guest_cr(), so that no flushes occur when
> the bit was set.
> 
> Signed-off-by: Razvan Cojocaru <rcojocaru@xxxxxxxxxxxxxxx>
> Reported-by: Bitweasil <bitweasil@xxxxxxxxxxxxxx>
> Suggested-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> Acked-by: Tamas K Lengyel <tamas@xxxxxxxxxxxxx>

Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel