From: Paolo Bonzini <pbonzini@redhat.com>
To: Krish Sadhukhan <krish.sadhukhan@oracle.com>,
Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Jim Mattson <jmattson@google.com>, kvm list <kvm@vger.kernel.org>
Subject: Re: [PATCH 1/2 v2] KVM: nVMX: KVM needs to unset "unrestricted guest" VM-execution control in vmcs02 if vmcs12 doesn't set it
Date: Tue, 28 Apr 2020 10:14:17 +0200 [thread overview]
Message-ID: <11ce961c-d98c-3c4c-06a7-3c0f8336a340@redhat.com> (raw)
In-Reply-To: <02a49d40-fe80-2715-d9a8-17770e72c7a3@oracle.com>
On 28/04/20 09:25, Krish Sadhukhan wrote:
>>>
>> Absolutely. Unrestricted guest requires EPT, but EPT is invisible to
>> the guest. (Currently EPT requires guest MAXPHYADDR = host MAXPHYADDR,
>> in the sense that the guest can detect that the host is lying about
>> MAXPHYADDR; but that is really a bug that I hope will be fixed in 5.8,
>> relaxing the requirement to guest MAXPHYADDR <= host PHYADDR).
>
> Should EPT for the nested guest be set up in the normal way (PML4E ->
> PDPTE-> PDE -> PTE) when GUEST_CR0.PE is zero ? Or does it have to be a
> special set up like only the PTEs are needed because no protection and
> no paging are used ?
I don't understand. When EPT is in use, the vmcs02 CR3 is simply set to
the vmcs12 CR3.
Paolo
next prev parent reply other threads:[~2020-04-28 8:14 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-15 18:30 [PATCH 0/2 v2] kvm-unit-test: nVMX: Test Selector and Base Address fields of Guest Segment registers Krish Sadhukhan
2020-04-15 18:30 ` [PATCH 1/2 v2] KVM: nVMX: KVM needs to unset "unrestricted guest" VM-execution control in vmcs02 if vmcs12 doesn't set it Krish Sadhukhan
2020-04-15 19:30 ` Sean Christopherson
2020-04-15 20:18 ` Jim Mattson
2020-04-16 9:18 ` Paolo Bonzini
2020-04-18 1:29 ` Krish Sadhukhan
2020-04-18 1:55 ` Sean Christopherson
2020-04-18 9:53 ` Paolo Bonzini
2020-04-20 15:12 ` Sean Christopherson
2020-04-28 7:25 ` Krish Sadhukhan
2020-04-28 8:14 ` Paolo Bonzini [this message]
2020-04-28 17:38 ` Krish Sadhukhan
2020-04-28 18:00 ` Jim Mattson
2020-04-15 18:30 ` [PATCH 2/2 v2] kvm-unit-tests: nVMX: Test Selector and Base Address fields of Guest Segment Registers on vmentry of nested guests Krish Sadhukhan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=11ce961c-d98c-3c4c-06a7-3c0f8336a340@redhat.com \
--to=pbonzini@redhat.com \
--cc=jmattson@google.com \
--cc=krish.sadhukhan@oracle.com \
--cc=kvm@vger.kernel.org \
--cc=sean.j.christopherson@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.