All of lore.kernel.org
 help / color / mirror / Atom feed
From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
	kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 09/10] KVM: VMX: Move nested EPT out of kvm_x86_ops.get_tdp_level() hook
Date: Fri,  1 May 2020 21:32:33 -0700	[thread overview]
Message-ID: <20200502043234.12481-10-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20200502043234.12481-1-sean.j.christopherson@intel.com>

Separate the "core" TDP level handling from the nested EPT path to make
it clear that kvm_x86_ops.get_tdp_level() is used if and only if nested
EPT is not in use (kvm_init_shadow_ept_mmu() calculates the level from
the passed in vmcs12->eptp).  Add a WARN_ON() to enforce that the
kvm_x86_ops hook is not called for nested EPT.

This sets the stage for snapshotting the non-"nested EPT" TDP page level
during kvm_cpuid_update() to avoid the retpoline associated with
kvm_x86_ops.get_tdp_level() when resetting the MMU, a relatively
frequent operation when running a nested guest.

No functional change intended.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 arch/x86/kvm/vmx/vmx.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d826ac541eed..c9c6e72e9660 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -3006,15 +3006,23 @@ void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
 	vmx->emulation_required = emulation_required(vcpu);
 }
 
-static int get_ept_level(struct kvm_vcpu *vcpu)
+static int vmx_get_tdp_level(struct kvm_vcpu *vcpu)
 {
-	if (is_guest_mode(vcpu) && nested_cpu_has_ept(get_vmcs12(vcpu)))
-		return vmx_eptp_page_walk_level(nested_ept_get_eptp(vcpu));
+	WARN_ON(is_guest_mode(vcpu) && nested_cpu_has_ept(get_vmcs12(vcpu)));
+
 	if (cpu_has_vmx_ept_5levels() && (cpuid_maxphyaddr(vcpu) > 48))
 		return 5;
 	return 4;
 }
 
+static int get_ept_level(struct kvm_vcpu *vcpu)
+{
+	if (is_guest_mode(vcpu) && nested_cpu_has_ept(get_vmcs12(vcpu)))
+		return vmx_eptp_page_walk_level(nested_ept_get_eptp(vcpu));
+
+	return vmx_get_tdp_level(vcpu);
+}
+
 u64 construct_eptp(struct kvm_vcpu *vcpu, unsigned long root_hpa)
 {
 	u64 eptp = VMX_EPTP_MT_WB;
@@ -7832,7 +7840,7 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
 
 	.set_tss_addr = vmx_set_tss_addr,
 	.set_identity_map_addr = vmx_set_identity_map_addr,
-	.get_tdp_level = get_ept_level,
+	.get_tdp_level = vmx_get_tdp_level,
 	.get_mt_mask = vmx_get_mt_mask,
 
 	.get_exit_info = vmx_get_exit_info,
-- 
2.26.0


  parent reply	other threads:[~2020-05-02  4:32 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-02  4:32 [PATCH 00/10] KVM: x86: Misc anti-retpoline optimizations Sean Christopherson
2020-05-02  4:32 ` [PATCH 01/10] KVM: x86: Save L1 TSC offset in 'struct kvm_vcpu_arch' Sean Christopherson
2020-05-02  4:32 ` [PATCH 02/10] KVM: nVMX: Unconditionally validate CR3 during nested transitions Sean Christopherson
2020-05-02  4:32 ` [PATCH 03/10] KVM: x86: Make kvm_x86_ops' {g,s}et_dr6() hooks optional Sean Christopherson
2020-05-04 13:19   ` Paolo Bonzini
2020-05-02  4:32 ` [PATCH 04/10] KVM: x86: Split guts of kvm_update_dr7() to separate helper Sean Christopherson
2020-05-02  4:32 ` [PATCH 05/10] KVM: nVMX: Avoid retpoline when writing DR7 during nested transitions Sean Christopherson
2020-05-02  4:32 ` [PATCH 06/10] KVM: VMX: Add proper cache tracking for CR4 Sean Christopherson
2020-05-02  4:32 ` [PATCH 07/10] KVM: VMX: Add proper cache tracking for CR0 Sean Christopherson
2020-05-02  4:32 ` [PATCH 08/10] KVM: VMX: Add anti-retpoline accessors for RIP and RSP Sean Christopherson
2020-05-02  4:32 ` Sean Christopherson [this message]
2020-05-02  4:32 ` [PATCH 10/10] KVM: x86/mmu: Capture TDP level when updating CPUID Sean Christopherson
2020-05-04 13:25 ` [PATCH 00/10] KVM: x86: Misc anti-retpoline optimizations Paolo Bonzini
2020-05-04 15:09   ` Sean Christopherson

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=20200502043234.12481-10-sean.j.christopherson@intel.com \
    --to=sean.j.christopherson@intel.com \
    --cc=jmattson@google.com \
    --cc=joro@8bytes.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=pbonzini@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 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.