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Message-Id: <20211124122055.64424-10-jiangshanlai@gmail.com>
Date: Wed, 24 Nov 2021 20:20:51 +0800
From: Lai Jiangshan <jiangshanlai@...il.com>
To: linux-kernel@...r.kernel.org
Cc: kvm@...r.kernel.org, Lai Jiangshan <laijs@...ux.alibaba.com>,
Paolo Bonzini <pbonzini@...hat.com>,
Jonathan Corbet <corbet@....net>,
Sean Christopherson <seanjc@...gle.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>,
Wanpeng Li <wanpengli@...cent.com>,
Jim Mattson <jmattson@...gle.com>,
Joerg Roedel <joro@...tes.org>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
Dave Hansen <dave.hansen@...ux.intel.com>, x86@...nel.org,
"H. Peter Anvin" <hpa@...or.com>, linux-doc@...r.kernel.org
Subject: [PATCH 09/12] KVM: X86: Rename gpte_is_8_bytes to has_4_byte_gpte and invert the direction
From: Lai Jiangshan <laijs@...ux.alibaba.com>
It's a bit more confusing to make gpte_is_8_bytes=1 if there are no
guest PTEs at all. And has_4_byte_gpte is only changed to be only set
when there are guest PTEs and the guest PTE size is 4 bytes. So when
nonpaping, the value is not inverted, it is still false.
Suggested-by: Paolo Bonzini <pbonzini@...hat.com>
Signed-off-by: Lai Jiangshan <laijs@...ux.alibaba.com>
---
Documentation/virt/kvm/mmu.rst | 8 ++++----
arch/x86/include/asm/kvm_host.h | 8 ++++----
arch/x86/kvm/mmu/mmu.c | 12 ++++++------
arch/x86/kvm/mmu/mmutrace.h | 2 +-
arch/x86/kvm/mmu/tdp_mmu.c | 2 +-
5 files changed, 16 insertions(+), 16 deletions(-)
diff --git a/Documentation/virt/kvm/mmu.rst b/Documentation/virt/kvm/mmu.rst
index f60f5488e121..5b1ebad24c77 100644
--- a/Documentation/virt/kvm/mmu.rst
+++ b/Documentation/virt/kvm/mmu.rst
@@ -161,7 +161,7 @@ Shadow pages contain the following information:
If clear, this page corresponds to a guest page table denoted by the gfn
field.
role.quadrant:
- When role.gpte_is_8_bytes=0, the guest uses 32-bit gptes while the host uses 64-bit
+ When role.has_4_byte_gpte=1, the guest uses 32-bit gptes while the host uses 64-bit
sptes. That means a guest page table contains more ptes than the host,
so multiple shadow pages are needed to shadow one guest page.
For first-level shadow pages, role.quadrant can be 0 or 1 and denotes the
@@ -177,9 +177,9 @@ Shadow pages contain the following information:
The page is invalid and should not be used. It is a root page that is
currently pinned (by a cpu hardware register pointing to it); once it is
unpinned it will be destroyed.
- role.gpte_is_8_bytes:
- Reflects the size of the guest PTE for which the page is valid, i.e. '1'
- if 64-bit gptes are in use, '0' if 32-bit gptes are in use.
+ role.has_4_byte_gpte:
+ Reflects the size of the guest PTE for which the page is valid, i.e. '0'
+ if direct map or 64-bit gptes are in use, '1' if 32-bit gptes are in use.
role.efer_nx:
Contains the value of efer.nx for which the page is valid.
role.cr0_wp:
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e382596baa1d..01e50703c878 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -296,14 +296,14 @@ struct kvm_kernel_irq_routing_entry;
*
* - invalid shadow pages are not accounted, so the bits are effectively 18
*
- * - quadrant will only be used if gpte_is_8_bytes=0 (non-PAE paging);
+ * - quadrant will only be used if has_4_byte_gpte=1 (non-PAE paging);
* execonly and ad_disabled are only used for nested EPT which has
- * gpte_is_8_bytes=1. Therefore, 2 bits are always unused.
+ * has_4_byte_gpte=0. Therefore, 2 bits are always unused.
*
* - the 4 bits of level are effectively limited to the values 2/3/4/5,
* as 4k SPs are not tracked (allowed to go unsync). In addition non-PAE
* paging has exactly one upper level, making level completely redundant
- * when gpte_is_8_bytes=0.
+ * when has_4_byte_gpte=1.
*
* - on top of this, smep_andnot_wp and smap_andnot_wp are only set if
* cr0_wp=0, therefore these three bits only give rise to 5 possibilities.
@@ -315,7 +315,7 @@ union kvm_mmu_page_role {
u32 word;
struct {
unsigned level:4;
- unsigned gpte_is_8_bytes:1;
+ unsigned has_4_byte_gpte:1;
unsigned quadrant:2;
unsigned direct:1;
unsigned access:3;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index f5a1da112daf..9fb9927264d8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -2077,7 +2077,7 @@ static struct kvm_mmu_page *kvm_mmu_get_page(struct kvm_vcpu *vcpu,
role.level = level;
role.direct = direct;
role.access = access;
- if (!direct_mmu && !role.gpte_is_8_bytes) {
+ if (role.has_4_byte_gpte) {
quadrant = gaddr >> (PAGE_SHIFT + (PT64_PT_BITS * level));
quadrant &= (1 << ((PT32_PT_BITS - PT64_PT_BITS) * level)) - 1;
role.quadrant = quadrant;
@@ -4727,7 +4727,7 @@ kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu,
role.base.ad_disabled = (shadow_accessed_mask == 0);
role.base.level = kvm_mmu_get_tdp_level(vcpu);
role.base.direct = true;
- role.base.gpte_is_8_bytes = true;
+ role.base.has_4_byte_gpte = false;
return role;
}
@@ -4772,7 +4772,7 @@ kvm_calc_shadow_root_page_role_common(struct kvm_vcpu *vcpu,
role.base.smep_andnot_wp = role.ext.cr4_smep && !____is_cr0_wp(regs);
role.base.smap_andnot_wp = role.ext.cr4_smap && !____is_cr0_wp(regs);
- role.base.gpte_is_8_bytes = ____is_cr0_pg(regs) && ____is_cr4_pae(regs);
+ role.base.has_4_byte_gpte = ____is_cr0_pg(regs) && !____is_cr4_pae(regs);
return role;
}
@@ -4871,7 +4871,7 @@ kvm_calc_shadow_ept_root_page_role(struct kvm_vcpu *vcpu, bool accessed_dirty,
role.base.smm = vcpu->arch.root_mmu.mmu_role.base.smm;
role.base.level = level;
- role.base.gpte_is_8_bytes = true;
+ role.base.has_4_byte_gpte = false;
role.base.direct = false;
role.base.ad_disabled = !accessed_dirty;
role.base.guest_mode = true;
@@ -5155,7 +5155,7 @@ static bool detect_write_misaligned(struct kvm_mmu_page *sp, gpa_t gpa,
gpa, bytes, sp->role.word);
offset = offset_in_page(gpa);
- pte_size = sp->role.gpte_is_8_bytes ? 8 : 4;
+ pte_size = sp->role.has_4_byte_gpte ? 4 : 8;
/*
* Sometimes, the OS only writes the last one bytes to update status
@@ -5179,7 +5179,7 @@ static u64 *get_written_sptes(struct kvm_mmu_page *sp, gpa_t gpa, int *nspte)
page_offset = offset_in_page(gpa);
level = sp->role.level;
*nspte = 1;
- if (!sp->role.gpte_is_8_bytes) {
+ if (sp->role.has_4_byte_gpte) {
page_offset <<= 1; /* 32->64 */
/*
* A 32-bit pde maps 4MB while the shadow pdes map
diff --git a/arch/x86/kvm/mmu/mmutrace.h b/arch/x86/kvm/mmu/mmutrace.h
index b8151bbca36a..de5e8e4e1aa7 100644
--- a/arch/x86/kvm/mmu/mmutrace.h
+++ b/arch/x86/kvm/mmu/mmutrace.h
@@ -35,7 +35,7 @@
" %snxe %sad root %u %s%c", \
__entry->mmu_valid_gen, \
__entry->gfn, role.level, \
- role.gpte_is_8_bytes ? 8 : 4, \
+ role.has_4_byte_gpte ? 4 : 8, \
role.quadrant, \
role.direct ? " direct" : "", \
access_str[role.access], \
diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index 377a96718a2e..fb602c025d9d 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -165,7 +165,7 @@ static union kvm_mmu_page_role page_role_for_level(struct kvm_vcpu *vcpu,
role = vcpu->arch.mmu->mmu_role.base;
role.level = level;
role.direct = true;
- role.gpte_is_8_bytes = true;
+ role.has_4_byte_gpte = false;
role.access = ACC_ALL;
role.ad_disabled = !shadow_accessed_mask;
--
2.19.1.6.gb485710b
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