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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Cc: kvm@vger.kernel.org, pbonzini@redhat.com, jmattson@google.com
Subject: Re: [PATCH 3/4 v2] KVM: nSVM: Test non-MBZ reserved bits in CR3 in long mode
Date: Mon, 28 Sep 2020 20:11:55 -0700	[thread overview]
Message-ID: <20200929031154.GC31514@linux.intel.com> (raw)
In-Reply-To: <20200928072043.9359-4-krish.sadhukhan@oracle.com>

On Mon, Sep 28, 2020 at 07:20:42AM +0000, Krish Sadhukhan wrote:
> According to section "CR3" in APM vol. 2, the non-MBZ reserved bits in CR3
> need to be set by software as follows:
> 
> 	"Reserved Bits. Reserved fields should be cleared to 0 by software
> 	when writing CR3."

Nothing in the shortlog or changelog actually states what this patch does.
"Test non-MBZ reserved bits in CR3 in long mode" is rather ambiguous, and
IIUC, the changelog is straight up misleading.

Based on the discussion from v1, I _think_ this test verifies that KVM does
_not_ fail nested VMRUN if non-MBZ bits are set, correct?

If so, then something like:

  KVM: nSVM: Verify non-MBZ CR3 reserved bits can be set in long mode

with further explanation in the changelog would be very helpful.

  reply	other threads:[~2020-09-29  3:11 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-09-28  7:20 [PATCH 0/4 v2] KVM: nSVM: Add checks for CR3 and CR4 reserved bits to svm_set_nested_state() and test CR3 non-MBZ reserved bits Krish Sadhukhan
2020-09-28  7:20 ` [PATCH 1/4 v2] KVM: nSVM: CR3 MBZ bits are only 63:52 Krish Sadhukhan
2020-09-28  7:20 ` [PATCH 2/4 v2] KVM: nSVM: Add check for reserved bits for CR3, CR4, DR6, DR7 and EFER to svm_set_nested_state() Krish Sadhukhan
2020-09-28  7:20 ` [PATCH 3/4 v2] KVM: nSVM: Test non-MBZ reserved bits in CR3 in long mode Krish Sadhukhan
2020-09-29  3:11   ` Sean Christopherson [this message]
2020-10-01  0:29     ` Krish Sadhukhan
2020-10-01  0:50       ` Sean Christopherson
2020-10-05 19:10         ` Krish Sadhukhan
2020-09-28  7:20 ` [PATCH 4/4 v2] KVM: nSVM: nested_vmcb_checks() needs to check all bits of EFER Krish Sadhukhan

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