[PATCH v2 3/9] KVM: x86: MMU: Rename get_cr3() --> get_pgd() and clear high bits for pgd

[Robert Hoo <robert.hu@xxxxxxxxxxxxxxx>]

The get_cr3() is the implementation of kvm_mmu::get_guest_pgd(), well, CR3
cannot be naturally equivalent to pgd, SDM says CR3 high bits are reserved,
must be zero.
And now, with LAM feature's introduction, bit 61 ~ 62 are used.
So, rename get_cr3() --> get_pgd() to better indicate function purpose and
in it, filtered out CR3 high bits.

Signed-off-by: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx>
Reviewed-by: Jingqi Liu <jingqi.liu@xxxxxxxxx>
---
 arch/x86/include/asm/processor-flags.h |  1 +
 arch/x86/kvm/mmu/mmu.c                 | 12 ++++++++----
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/include/asm/processor-flags.h b/arch/x86/include/asm/processor-flags.h
index d8cccadc83a6..bb0f8dd16956 100644
--- a/arch/x86/include/asm/processor-flags.h
+++ b/arch/x86/include/asm/processor-flags.h
@@ -38,6 +38,7 @@
 #ifdef CONFIG_X86_64
 /* Mask off the address space ID and SME encryption bits. */
 #define CR3_ADDR_MASK	__sme_clr(PHYSICAL_PAGE_MASK)
+#define CR3_HIGH_RSVD_MASK	GENMASK_ULL(63, 52)
 #define CR3_PCID_MASK	0xFFFull
 #define CR3_NOFLUSH	BIT_ULL(63)
 
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 6f81539061d6..04e4b38fe73a 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4487,9 +4487,13 @@ void kvm_mmu_new_pgd(struct kvm_vcpu *vcpu, gpa_t new_pgd)
 }
 EXPORT_SYMBOL_GPL(kvm_mmu_new_pgd);
 
-static unsigned long get_cr3(struct kvm_vcpu *vcpu)
+static unsigned long get_pgd(struct kvm_vcpu *vcpu)
 {
+#ifdef CONFIG_X86_64
+	return kvm_read_cr3(vcpu) & ~CR3_HIGH_RSVD_MASK;
+#else
 	return kvm_read_cr3(vcpu);
+#endif
 }
 
 static bool sync_mmio_spte(struct kvm_vcpu *vcpu, u64 *sptep, gfn_t gfn,
@@ -5042,7 +5046,7 @@ static void init_kvm_tdp_mmu(struct kvm_vcpu *vcpu,
 	context->page_fault = kvm_tdp_page_fault;
 	context->sync_page = nonpaging_sync_page;
 	context->invlpg = NULL;
-	context->get_guest_pgd = get_cr3;
+	context->get_guest_pgd = get_pgd;
 	context->get_pdptr = kvm_pdptr_read;
 	context->inject_page_fault = kvm_inject_page_fault;
 
@@ -5192,7 +5196,7 @@ static void init_kvm_softmmu(struct kvm_vcpu *vcpu,
 
 	kvm_init_shadow_mmu(vcpu, cpu_role);
 
-	context->get_guest_pgd     = get_cr3;
+	context->get_guest_pgd     = get_pgd;
 	context->get_pdptr         = kvm_pdptr_read;
 	context->inject_page_fault = kvm_inject_page_fault;
 }
@@ -5206,7 +5210,7 @@ static void init_kvm_nested_mmu(struct kvm_vcpu *vcpu,
 		return;
 
 	g_context->cpu_role.as_u64   = new_mode.as_u64;
-	g_context->get_guest_pgd     = get_cr3;
+	g_context->get_guest_pgd     = get_pgd;
 	g_context->get_pdptr         = kvm_pdptr_read;
 	g_context->inject_page_fault = kvm_inject_page_fault;
 
-- 
2.31.1