From: Binbin Wu <binbin.wu@linux.intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: seanjc@google.com, pbonzini@redhat.com, chao.gao@intel.com,
kai.huang@intel.com, David.Laight@ACULAB.COM,
robert.hu@linux.intel.com, guang.zeng@intel.com,
binbin.wu@linux.intel.com
Subject: [PATCH v11 05/16] KVM: x86/mmu: Drop non-PA bits when getting GFN for guest's PGD
Date: Wed, 13 Sep 2023 20:42:16 +0800 [thread overview]
Message-ID: <20230913124227.12574-6-binbin.wu@linux.intel.com> (raw)
In-Reply-To: <20230913124227.12574-1-binbin.wu@linux.intel.com>
Drop non-PA bits when getting GFN for guest's PGD with the maximum theoretical
mask for guest MAXPHYADDR.
Do it unconditionally because it's harmless for 32-bit guests, querying 64-bit
mode would be more expensive, and for EPT the mask isn't tied to guest mode.
Using PT_BASE_ADDR_MASK would be technically wrong (PAE paging has 64-bit
elements _excpet_ for CR3, which has only 32 valid bits), it wouldn't matter
in practice though.
Opportunistically use GENMASK_ULL() to define __PT_BASE_ADDR_MASK.
Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Tested-by: Xuelian Guo <xuelian.guo@intel.com>
---
arch/x86/kvm/mmu/mmu.c | 2 +-
arch/x86/kvm/mmu/mmu_internal.h | 1 +
arch/x86/kvm/mmu/paging_tmpl.h | 2 +-
3 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e1d011c67cc6..f316df038e61 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3774,7 +3774,7 @@ static int mmu_alloc_shadow_roots(struct kvm_vcpu *vcpu)
hpa_t root;
root_pgd = kvm_mmu_get_guest_pgd(vcpu, mmu);
- root_gfn = root_pgd >> PAGE_SHIFT;
+ root_gfn = (root_pgd & __PT_BASE_ADDR_MASK) >> PAGE_SHIFT;
if (!kvm_vcpu_is_visible_gfn(vcpu, root_gfn)) {
mmu->root.hpa = kvm_mmu_get_dummy_root();
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index b102014e2c60..b5aca7560fd0 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -13,6 +13,7 @@
#endif
/* Page table builder macros common to shadow (host) PTEs and guest PTEs. */
+#define __PT_BASE_ADDR_MASK GENMASK_ULL(51, 12)
#define __PT_LEVEL_SHIFT(level, bits_per_level) \
(PAGE_SHIFT + ((level) - 1) * (bits_per_level))
#define __PT_INDEX(address, level, bits_per_level) \
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index c85255073f67..4d4e98fe4f35 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -62,7 +62,7 @@
#endif
/* Common logic, but per-type values. These also need to be undefined. */
-#define PT_BASE_ADDR_MASK ((pt_element_t)(((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1)))
+#define PT_BASE_ADDR_MASK ((pt_element_t)__PT_BASE_ADDR_MASK)
#define PT_LVL_ADDR_MASK(lvl) __PT_LVL_ADDR_MASK(PT_BASE_ADDR_MASK, lvl, PT_LEVEL_BITS)
#define PT_LVL_OFFSET_MASK(lvl) __PT_LVL_OFFSET_MASK(PT_BASE_ADDR_MASK, lvl, PT_LEVEL_BITS)
#define PT_INDEX(addr, lvl) __PT_INDEX(addr, lvl, PT_LEVEL_BITS)
--
2.25.1
next prev parent reply other threads:[~2023-09-13 15:40 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-13 12:42 [PATCH v11 00/16] LAM and LASS KVM Enabling Binbin Wu
2023-09-13 12:42 ` [PATCH v11 01/16] KVM: x86: Consolidate flags for __linearize() Binbin Wu
2023-09-13 12:42 ` [PATCH v11 02/16] KVM: x86: Use a new flag for branch targets Binbin Wu
2023-10-23 16:20 ` Sean Christopherson
2023-09-13 12:42 ` [PATCH v11 03/16] KVM: x86: Add an emulation flag for implicit system access Binbin Wu
2023-09-13 12:42 ` [PATCH v11 04/16] KVM: x86: Add X86EMUL_F_INVLPG and pass it in em_invlpg() Binbin Wu
2023-09-13 12:42 ` Binbin Wu [this message]
2023-09-13 12:42 ` [PATCH v11 06/16] KVM: x86: Add & use kvm_vcpu_is_legal_cr3() to check CR3's legality Binbin Wu
2023-09-13 12:42 ` [PATCH v11 07/16] KVM: x86: Remove kvm_vcpu_is_illegal_gpa() Binbin Wu
2023-09-13 12:42 ` [PATCH v11 08/16] KVM: x86: Introduce get_untagged_addr() in kvm_x86_ops and call it in emulator Binbin Wu
2023-10-23 23:14 ` Sean Christopherson
2023-10-23 23:30 ` Sean Christopherson
2023-09-13 12:42 ` [PATCH v11 09/16] KVM: x86: Untag address for vmexit handlers when LAM applicable Binbin Wu
2023-09-13 12:42 ` [PATCH v11 10/16] KVM: x86: Virtualize LAM for supervisor pointer Binbin Wu
2023-09-13 12:42 ` [PATCH v11 11/16] KVM: x86: Virtualize LAM for user pointer Binbin Wu
2023-09-13 12:42 ` [PATCH v11 12/16] KVM: x86: Advertise and enable LAM (user and supervisor) Binbin Wu
2023-09-13 12:42 ` [PATCH v11 13/16] KVM: x86: Use KVM-governed feature framework to track "LAM enabled" Binbin Wu
2023-09-13 12:42 ` [PATCH v11 14/16] KVM: emulator: Add emulation of LASS violation checks on linear address Binbin Wu
2023-09-13 12:42 ` [PATCH v11 15/16] KVM: VMX: Virtualize LASS Binbin Wu
2023-09-13 12:42 ` [PATCH v11 16/16] KVM: x86: Advertise LASS CPUID to user space Binbin Wu
2023-10-08 9:37 ` [PATCH v11 00/16] LAM and LASS KVM Enabling Binbin Wu
2023-10-10 23:48 ` Sean Christopherson
2023-10-21 0:26 ` Sean Christopherson
2023-10-21 0:34 ` Sean Christopherson
2023-10-22 12:35 ` Binbin Wu
2023-10-23 23:43 ` Sean Christopherson
2023-10-24 8:31 ` Binbin Wu
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