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

["Jan Beulich" <JBeulich@xxxxxxxx>]

>>> On 19.02.18 at 09:48, <rcojocaru@xxxxxxxxxxxxxxx> wrote:
> On 02/16/2018 01:17 PM, Jan Beulich wrote:
>>>>> 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>
> 
> Should I rebase this because of commit
> 24470b99c1671dca531c2cf5747eda2f8892ecbc?

Well, if that change introduces some conflict with yours, then
generally the (obvious) answer is "yes". Considering that your
patch doesn't have all necessary acks yet, whether you wait
until you have those is up to you (as alternatively there may be
further requests for changes to make).

Jan


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