From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
linux-kernel@vger.kernel.org, "Jim Mattson" <jmattson@google.com>,
"Liran Alon" <liran.alon@oracle.com>
Subject: [PATCH 8/9] x86/kvm/mmu: check if tdp/shadow MMU reconfiguration is needed
Date: Thu, 2 Aug 2018 12:01:31 +0200 [thread overview]
Message-ID: <20180802100132.5249-9-vkuznets@redhat.com> (raw)
In-Reply-To: <20180802100132.5249-1-vkuznets@redhat.com>
MMU reconfiguration in init_kvm_tdp_mmu()/kvm_init_shadow_mmu() can be
avoided if the source data used to configure it didn't change; enhance
kvm_mmu_scache with the required fields and consolidate common code in
kvm_calc_mmu_role_common().
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/include/asm/kvm_host.h | 2 +
arch/x86/kvm/mmu.c | 86 ++++++++++++++++++++++++-----------------
2 files changed, 52 insertions(+), 36 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index d44668dcf655..f3f5cacb5727 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -283,10 +283,12 @@ union kvm_mmu_scache {
struct {
unsigned int valid:1;
unsigned int execonly:1;
+ unsigned int cr0_pg:1;
unsigned int cr4_pse:1;
unsigned int cr4_pke:1;
unsigned int cr4_smap:1;
unsigned int cr4_smep:1;
+ unsigned int cr4_la57:1;
};
};
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index c46f875bf937..c621d9892a37 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4679,34 +4679,40 @@ static void paging32E_init_context(struct kvm_vcpu *vcpu,
}
static union kvm_mmu_role
-kvm_calc_mmu_role_common(struct kvm_vcpu *vcpu)
+kvm_calc_mmu_role_common(struct kvm_vcpu *vcpu, bool mmu_init)
{
union kvm_mmu_role role = {0};
role.base_role.access = ACC_ALL;
+ role.base_role.nxe = !!is_nx(vcpu);
+ role.base_role.cr4_pae = !!is_pae(vcpu);
role.base_role.cr0_wp = is_write_protection(vcpu);
+ role.base_role.smm = is_smm(vcpu);
+ role.base_role.guest_mode = is_guest_mode(vcpu);
+ if (!mmu_init)
+ return role;
+
+ role.scache.cr0_pg = !!is_paging(vcpu);
role.scache.cr4_smep = kvm_read_cr4_bits(vcpu, X86_CR4_SMEP) != 0;
role.scache.cr4_smap = kvm_read_cr4_bits(vcpu, X86_CR4_SMAP) != 0;
role.scache.cr4_pse = !!is_pse(vcpu);
role.scache.cr4_pke = kvm_read_cr4_bits(vcpu, X86_CR4_PKE) != 0;
+ role.scache.cr4_la57 = kvm_read_cr4_bits(vcpu, X86_CR4_LA57) != 0;
role.scache.valid = 1;
return role;
}
-static union kvm_mmu_page_role
-kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu)
+static union kvm_mmu_role
+kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu, bool mmu_init)
{
- union kvm_mmu_page_role role = {0};
+ union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu, mmu_init);
- role.guest_mode = is_guest_mode(vcpu);
- role.smm = is_smm(vcpu);
- role.ad_disabled = (shadow_accessed_mask == 0);
- role.level = kvm_x86_ops->get_tdp_level(vcpu);
- role.direct = true;
- role.access = ACC_ALL;
+ role.base_role.ad_disabled = (shadow_accessed_mask == 0);
+ role.base_role.level = kvm_x86_ops->get_tdp_level(vcpu);
+ role.base_role.direct = true;
return role;
}
@@ -4714,9 +4720,14 @@ kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu)
static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
{
struct kvm_mmu *context = vcpu->arch.mmu;
+ union kvm_mmu_role new_role =
+ kvm_calc_tdp_mmu_root_page_role(vcpu, true);
- context->mmu_role.base_role.word = mmu_base_role_mask.word &
- kvm_calc_tdp_mmu_root_page_role(vcpu).word;
+ new_role.base_role.word &= mmu_base_role_mask.word;
+ if (new_role.as_u64 == context->mmu_role.as_u64)
+ return;
+
+ context->mmu_role.as_u64 = new_role.as_u64;
context->page_fault = tdp_page_fault;
context->sync_page = nonpaging_sync_page;
context->invlpg = nonpaging_invlpg;
@@ -4756,29 +4767,23 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu)
reset_tdp_shadow_zero_bits_mask(vcpu, context);
}
-static union kvm_mmu_page_role
-kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu)
-{
- union kvm_mmu_page_role role = {0};
- bool smep = kvm_read_cr4_bits(vcpu, X86_CR4_SMEP);
- bool smap = kvm_read_cr4_bits(vcpu, X86_CR4_SMAP);
-
- role.nxe = is_nx(vcpu);
- role.cr4_pae = !!is_pae(vcpu);
- role.cr0_wp = is_write_protection(vcpu);
- role.smep_andnot_wp = smep && !is_write_protection(vcpu);
- role.smap_andnot_wp = smap && !is_write_protection(vcpu);
- role.guest_mode = is_guest_mode(vcpu);
- role.smm = is_smm(vcpu);
- role.direct = !is_paging(vcpu);
- role.access = ACC_ALL;
+static union kvm_mmu_role
+kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu, bool mmu_init)
+{
+ union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu, mmu_init);
+
+ role.base_role.smep_andnot_wp = role.scache.cr4_smep &&
+ !is_write_protection(vcpu);
+ role.base_role.smap_andnot_wp = role.scache.cr4_smap &&
+ !is_write_protection(vcpu);
+ role.base_role.direct = !is_paging(vcpu);
if (!is_long_mode(vcpu))
- role.level = PT32E_ROOT_LEVEL;
+ role.base_role.level = PT32E_ROOT_LEVEL;
else if (is_la57_mode(vcpu))
- role.level = PT64_ROOT_5LEVEL;
+ role.base_role.level = PT64_ROOT_5LEVEL;
else
- role.level = PT64_ROOT_4LEVEL;
+ role.base_role.level = PT64_ROOT_4LEVEL;
return role;
}
@@ -4786,6 +4791,12 @@ kvm_calc_shadow_mmu_root_page_role(struct kvm_vcpu *vcpu)
void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu)
{
struct kvm_mmu *context = vcpu->arch.mmu;
+ union kvm_mmu_role new_role =
+ kvm_calc_shadow_mmu_root_page_role(vcpu, true);
+
+ new_role.base_role.word &= mmu_base_role_mask.word;
+ if (new_role.as_u64 == context->mmu_role.as_u64)
+ return;
if (!is_paging(vcpu))
nonpaging_init_context(vcpu, context);
@@ -4796,8 +4807,7 @@ void kvm_init_shadow_mmu(struct kvm_vcpu *vcpu)
else
paging32_init_context(vcpu, context);
- context->mmu_role.base_role.word = mmu_base_role_mask.word &
- kvm_calc_shadow_mmu_root_page_role(vcpu).word;
+ context->mmu_role.as_u64 = new_role.as_u64;
reset_shadow_zero_bits_mask(vcpu, context);
}
EXPORT_SYMBOL_GPL(kvm_init_shadow_mmu);
@@ -4806,7 +4816,7 @@ static union kvm_mmu_role
kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty,
bool execonly)
{
- union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu);
+ union kvm_mmu_role role = kvm_calc_mmu_role_common(vcpu, true);
role.base_role.level = PT64_ROOT_4LEVEL;
role.base_role.direct = false;
@@ -4931,10 +4941,14 @@ EXPORT_SYMBOL_GPL(kvm_init_mmu);
static union kvm_mmu_page_role
kvm_mmu_calc_root_page_role(struct kvm_vcpu *vcpu)
{
+ union kvm_mmu_role role;
+
if (tdp_enabled)
- return kvm_calc_tdp_mmu_root_page_role(vcpu);
+ role = kvm_calc_tdp_mmu_root_page_role(vcpu, false);
else
- return kvm_calc_shadow_mmu_root_page_role(vcpu);
+ role = kvm_calc_shadow_mmu_root_page_role(vcpu, false);
+
+ return role.base_role;
}
void kvm_mmu_reset_context(struct kvm_vcpu *vcpu)
--
2.14.4
next prev parent reply other threads:[~2018-08-02 10:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-02 10:01 [PATCH 0/9] x86/kvm/nVMX: optimize MMU switch between L1 and L2 Vitaly Kuznetsov
2018-08-02 10:01 ` [PATCH 1/9] x86/kvm/mmu: make vcpu->mmu a pointer to the current MMU Vitaly Kuznetsov
2018-08-02 10:01 ` [PATCH 2/9] x86/kvm/mmu.c: set get_pdptr hook in kvm_init_shadow_ept_mmu() Vitaly Kuznetsov
2018-08-02 10:01 ` [PATCH 3/9] x86/kvm/mmu.c: add kvm_mmu parameter to kvm_mmu_free_roots() Vitaly Kuznetsov
2018-08-02 10:01 ` [PATCH 4/9] x86/kvm/mmu: introduce guest_mmu Vitaly Kuznetsov
2018-08-02 10:01 ` [PATCH 5/9] x86/kvm/mmu: get rid of redundant kvm_mmu_setup() Vitaly Kuznetsov
2018-08-02 10:01 ` [PATCH 6/9] x86/kvm/mmu: make space for source data caching in struct kvm_mmu Vitaly Kuznetsov
2018-09-19 15:54 ` Sean Christopherson
2018-09-20 8:12 ` Vitaly Kuznetsov
2018-08-02 10:01 ` [PATCH 7/9] x86/kvm/nVMX: introduce scache for kvm_init_shadow_ept_mmu Vitaly Kuznetsov
2018-08-02 10:01 ` Vitaly Kuznetsov [this message]
2018-08-02 10:01 ` [PATCH 9/9] x86/kvm/mmu: check if MMU reconfiguration is needed in init_kvm_nested_mmu() Vitaly Kuznetsov
2018-08-02 10:27 ` [PATCH 0/9] x86/kvm/nVMX: optimize MMU switch between L1 and L2 Paolo Bonzini
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=20180802100132.5249-9-vkuznets@redhat.com \
--to=vkuznets@redhat.com \
--cc=jmattson@google.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=liran.alon@oracle.com \
--cc=pbonzini@redhat.com \
--cc=rkrcmar@redhat.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