KVM: nVMX: Truncate base/index GPR value on address calc in !64-bit

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@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422022128.3464144-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index f93ff23..ac838fb 100644 (file)
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4619,9 +4619,9 @@ int get_vmx_mem_address(struct kvm_vcpu *vcpu, unsigned long exit_qualification,
        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);
 
        /*