kvmarm.lists.cs.columbia.edu archive mirror
 help / color / mirror / Atom feed
From: Sean Christopherson <sean.j.christopherson@intel.com>
To: "Marc Zyngier" <maz@kernel.org>,
	"James Hogan" <jhogan@kernel.org>,
	"Paul Mackerras" <paulus@ozlabs.org>,
	"Christian Borntraeger" <borntraeger@de.ibm.com>,
	"Janosch Frank" <frankja@linux.ibm.com>,
	"Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>
Cc: kvm-ppc@vger.kernel.org, Wanpeng Li <wanpengli@tencent.com>,
	kvm@vger.kernel.org, David Hildenbrand <david@redhat.com>,
	Joerg Roedel <joro@8bytes.org>, Cornelia Huck <cohuck@redhat.com>,
	linux-mips@vger.kernel.org,
	Sean Christopherson <sean.j.christopherson@intel.com>,
	linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	kvmarm@lists.cs.columbia.edu, Jim Mattson <jmattson@google.com>
Subject: [PATCH 21/45] KVM: x86: Remove spurious clearing of async #PF MSR
Date: Mon, 21 Oct 2019 18:59:01 -0700	[thread overview]
Message-ID: <20191022015925.31916-22-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20191022015925.31916-1-sean.j.christopherson@intel.com>

Remove a bogus clearing of apf.msr_val from kvm_arch_vcpu_destroy().

apf.msr_val is only set to a non-zero value by kvm_pv_enable_async_pf(),
which is only reachable by kvm_set_msr_common(), i.e. by writing
MSR_KVM_ASYNC_PF_EN.  KVM does not autonomously write said MSR, i.e.
can only be written via KVM_SET_MSRS or KVM_RUN.  Since KVM_SET_MSRS and
KVM_RUN are vcpu ioctls, they require a valid vcpu file descriptor.
kvm_arch_vcpu_destroy() is only called if KVM_CREATE_VCPU fails, and KVM
declares KVM_CREATE_VCPU successful once the vcpu fd is installed and
thus visible to userspace.  Ergo, apf.msr_val cannot be non-zero when
kvm_arch_vcpu_destroy() is called.

Fixes: 344d9588a9df0 ("KVM: Add PV MSR to enable asynchronous page faults delivery.")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/x86.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index dd667df37d63..dfd5c5244a6b 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9097,8 +9097,6 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
 {
-	vcpu->arch.apf.msr_val = 0;
-
 	kvm_arch_vcpu_free(vcpu);
 }
 
-- 
2.22.0

_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm

  parent reply	other threads:[~2019-10-22  2:00 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-22  1:58 [PATCH 00/45] KVM: Refactor vCPU creation Sean Christopherson
2019-10-22  1:58 ` [PATCH 01/45] KVM: PPC: Book3S HV: Uninit vCPU if vcore creation fails Sean Christopherson
2019-10-24  7:04   ` Greg Kurz
2019-10-22  1:58 ` [PATCH 02/45] KVM: PPC: Book3S PR: Free shared page if mmu initialization fails Sean Christopherson
2019-10-24  7:05   ` Greg Kurz
2019-10-22  1:58 ` [PATCH 03/45] KVM: x86: Free wbinvd_dirty_mask if vCPU creation fails Sean Christopherson
2019-10-22  1:58 ` [PATCH 04/45] KVM: VMX: Allocate VPID after initializing VCPU Sean Christopherson
2019-10-22  1:58 ` [PATCH 05/45] KVM: VMX: Use direct vcpu pointer during vCPU create/free Sean Christopherson
2019-10-22  1:58 ` [PATCH 06/45] KVM: SVM: " Sean Christopherson
2019-10-22  1:58 ` [PATCH 07/45] KVM: x86: Allocate vcpu struct in common x86 code Sean Christopherson
2019-10-22  1:58 ` [PATCH 08/45] KVM: x86: Move FPU allocation to " Sean Christopherson
2019-10-22  1:58 ` [PATCH 09/45] KVM: x86: Move allocation of pio_data page down a few lines Sean Christopherson
2019-10-22  1:58 ` [PATCH 10/45] KVM: x86: Move kvm_vcpu_init() invocation to common code Sean Christopherson
2019-10-22  1:58 ` [PATCH 11/45] KVM: PPC: e500mc: Add build-time assert that vcpu is at offset 0 Sean Christopherson
2019-10-22  1:58 ` [PATCH 12/45] KVM: PPC: Allocate vcpu struct in common PPC code Sean Christopherson
2019-10-22  1:58 ` [PATCH 13/45] KVM: PPC: Book3S PR: Allocate book3s and shadow vcpu after common init Sean Christopherson
2019-10-22  1:58 ` [PATCH 14/45] KVM: PPC: e500mc: Move reset of oldpir below call to kvm_vcpu_init() Sean Christopherson
2019-10-22  1:58 ` [PATCH 15/45] KVM: PPC: Move kvm_vcpu_init() invocation to common code Sean Christopherson
2019-10-22  1:58 ` [PATCH 16/45] KVM: MIPS: Use kvm_vcpu_cache to allocate vCPUs Sean Christopherson
2019-10-22  1:58 ` [PATCH 17/45] KVM: MIPS: Drop kvm_arch_vcpu_free() Sean Christopherson
2019-10-22  1:58 ` [PATCH 18/45] KVM: PPC: " Sean Christopherson
2019-10-22  1:58 ` [PATCH 19/45] KVM: arm: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 20/45] KVM: x86: Remove spurious kvm_mmu_unload() from vcpu destruction path Sean Christopherson
2019-10-22  1:59 ` Sean Christopherson [this message]
2019-10-22  1:59 ` [PATCH 22/45] KVM: x86: Drop kvm_arch_vcpu_free() Sean Christopherson
2019-10-22  1:59 ` [PATCH 23/45] KVM: Remove kvm_arch_vcpu_free() declaration Sean Christopherson
2019-10-22  1:59 ` [PATCH 24/45] KVM: Add kvm_arch_vcpu_precreate() to handle pre-allocation issues Sean Christopherson
2019-10-22  1:59 ` [PATCH 25/45] KVM: s390: Move guts of kvm_arch_vcpu_init() into kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 26/45] KVM: s390: Invoke kvm_vcpu_init() before allocating sie_page Sean Christopherson
2019-10-22  1:59 ` [PATCH 27/45] KVM: MIPS: Invoke kvm_vcpu_uninit() immediately prior to freeing vcpu Sean Christopherson
2019-10-22  1:59 ` [PATCH 28/45] KVM: x86: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 29/45] KVM: Introduce kvm_vcpu_destroy() Sean Christopherson
2019-10-22  1:59 ` [PATCH 30/45] KVM: Move vcpu alloc and init invocation to common code Sean Christopherson
2019-10-22  1:59 ` [PATCH 31/45] KVM: Unexport kvm_vcpu_cache and kvm_{un}init_vcpu() Sean Christopherson
2019-10-22  1:59 ` [PATCH 32/45] KVM: Move initialization of preempt notifier to kvm_vcpu_init() Sean Christopherson
2019-10-22  1:59 ` [PATCH 33/45] KVM: x86: Move guts of kvm_arch_vcpu_setup() into kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 34/45] KVM: MIPS: Move .vcpu_setup() call to kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 35/45] KVM: s390: Manually invoke vcpu setup during kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 36/45] KVM: PPC: BookE: Setup vcpu during kvmppc_core_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 37/45] KVM: Drop kvm_arch_vcpu_setup() Sean Christopherson
2019-10-22  1:59 ` [PATCH 38/45] KVM: x86: Move all vcpu init code into kvm_arch_vcpu_create() Sean Christopherson
2019-10-22  1:59 ` [PATCH 39/45] KVM: MIPS: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 40/45] KVM: ARM: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 41/45] KVM: PPC: " Sean Christopherson
2019-10-22  1:59 ` [PATCH 42/45] KVM: arm64: Free sve_state via arm specific hook Sean Christopherson
2019-10-22 11:43   ` Christoffer Dall
2019-10-22 18:41     ` Sean Christopherson
2019-10-22  1:59 ` [PATCH 43/45] KVM: Drop kvm_arch_vcpu_init() and kvm_arch_vcpu_uninit() Sean Christopherson
2019-10-22  1:59 ` [PATCH 44/45] KVM: Move putting of vcpu->pid to kvm_vcpu_destroy() Sean Christopherson
2019-10-22  1:59 ` [PATCH 45/45] KVM: Move vcpu->run page allocation out of kvm_vcpu_init() Sean Christopherson
2019-10-22 11:51 ` [PATCH 00/45] KVM: Refactor vCPU creation Christoffer Dall

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=20191022015925.31916-22-sean.j.christopherson@intel.com \
    --to=sean.j.christopherson@intel.com \
    --cc=borntraeger@de.ibm.com \
    --cc=cohuck@redhat.com \
    --cc=david@redhat.com \
    --cc=frankja@linux.ibm.com \
    --cc=jhogan@kernel.org \
    --cc=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=kvm-ppc@vger.kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=kvmarm@lists.cs.columbia.edu \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mips@vger.kernel.org \
    --cc=maz@kernel.org \
    --cc=paulus@ozlabs.org \
    --cc=pbonzini@redhat.com \
    --cc=rkrcmar@redhat.com \
    --cc=vkuznets@redhat.com \
    --cc=wanpengli@tencent.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).