[PATCH 5.10 099/530] KVM: nVMX: Truncate base/index GPR value on address calc in !64-bit

[Greg Kroah-Hartman]

From: Sean Christopherson <seanjc@xxxxxxxxxx>

commit 82277eeed65eed6c6ee5b8f97bd978763eab148f upstream.

Drop bits 63:32 of the base and/or index GPRs when calculating the
effective address of a VMX instruction memory operand.  Outside of 64-bit
mode, memory encodings are strictly limited to E*X and below.

Fixes: 064aea774768 ("KVM: nVMX: Decoding memory operands of VMX instructions")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Message-Id: <20210422022128.3464144-7-seanjc@xxxxxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 arch/x86/kvm/vmx/nested.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4613,9 +4613,9 @@ int get_vmx_mem_address(struct kvm_vcpu
 	else if (addr_size == 0)
 		off = (gva_t)sign_extend64(off, 15);
 	if (base_is_valid)
-		off += kvm_register_read(vcpu, base_reg);
+		off += kvm_register_readl(vcpu, base_reg);
 	if (index_is_valid)
-		off += kvm_register_read(vcpu, index_reg) << scaling;
+		off += kvm_register_readl(vcpu, index_reg) << scaling;
 	vmx_get_segment(vcpu, &s, seg_reg);
 
 	/*