From ac8d6cad3c7b39633d5899dc2fa9abec7135e83e Mon Sep 17 00:00:00 2001 From: Hou Wenlong Date: Mon, 7 Mar 2022 20:26:33 +0800 Subject: KVM: x86: Only do MSR filtering when access MSR by rdmsr/wrmsr If MSR access is rejected by MSR filtering, kvm_set_msr()/kvm_get_msr() would return KVM_MSR_RET_FILTERED, and the return value is only handled well for rdmsr/wrmsr. However, some instruction emulation and state transition also use kvm_set_msr()/kvm_get_msr() to do msr access but may trigger some unexpected results if MSR access is rejected, E.g. RDPID emulation would inject a #UD but RDPID wouldn't cause a exit when RDPID is supported in hardware and ENABLE_RDTSCP is set. And it would also cause failure when load MSR at nested entry/exit. Since msr filtering is based on MSR bitmap, it is better to only do MSR filtering for rdmsr/wrmsr. Signed-off-by: Hou Wenlong Message-Id: <2b2774154f7532c96a6f04d71c82a8bec7d9e80b.1646655860.git.houwenlong.hwl@antgroup.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/emulate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/x86/kvm/emulate.c') diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index c9f87c079d88..be83c9c8482d 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3625,7 +3625,7 @@ static int em_wrmsr(struct x86_emulate_ctxt *ctxt) msr_data = (u32)reg_read(ctxt, VCPU_REGS_RAX) | ((u64)reg_read(ctxt, VCPU_REGS_RDX) << 32); - r = ctxt->ops->set_msr(ctxt, msr_index, msr_data); + r = ctxt->ops->set_msr_with_filter(ctxt, msr_index, msr_data); if (r == X86EMUL_IO_NEEDED) return r; @@ -3642,7 +3642,7 @@ static int em_rdmsr(struct x86_emulate_ctxt *ctxt) u64 msr_data; int r; - r = ctxt->ops->get_msr(ctxt, msr_index, &msr_data); + r = ctxt->ops->get_msr_with_filter(ctxt, msr_index, &msr_data); if (r == X86EMUL_IO_NEEDED) return r; -- cgit v1.2.3