Messages in this thread Patch in this message | | | Date | Fri, 12 Feb 2021 17:05:16 -0800 | Subject | [PATCH 7/9] KVM: x86/xen: Drop RAX[63:32] when processing hypercall | From | Sean Christopherson <> |
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Truncate RAX to 32 bits, i.e. consume EAX, when retrieving the hypecall index for a Xen hypercall. Per Xen documentation[*], the index is EAX when the vCPU is not in 64-bit mode.
[*] http://xenbits.xenproject.org/docs/sphinx-unstable/guest-guide/x86/hypercall-abi.html
Fixes: 23200b7a30de ("KVM: x86/xen: intercept xen hypercalls if enabled") Cc: Joao Martins <joao.m.martins@oracle.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/xen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index af8f6562fce4..5bfed72edd07 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -383,7 +383,7 @@ int kvm_xen_hypercall(struct kvm_vcpu *vcpu) bool longmode; u64 input, params[6]; - input = (u64)kvm_register_read(vcpu, VCPU_REGS_RAX); + input = (u64)kvm_register_readl(vcpu, VCPU_REGS_RAX); /* Hyper-V hypercalls get bit 31 set in EAX */ if ((input & 0x80000000) && -- 2.30.0.478.g8a0d178c01-goog
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