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SubjectRe: [PATCH] KVM: nvmx: retry writing guest memory after page fault injected
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> On 25 Dec 2019, at 4:21, linmiaohe <linmiaohe@huawei.com> wrote:
>
> From: Miaohe Lin <linmiaohe@huawei.com>
>
> We should retry writing guest memory when kvm_write_guest_virt_system()
> failed and page fault is injected in handle_vmread().
>
> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>

Patch fix seems correct to me:
Reviewed-by: Liran Alon <liran.alon@oracle.com>

However, I suggest to rephrase commit title & message as follows:

"""
KVM: nVMX: vmread should not set rflags to specify success in case of #PF

In case writing to vmread destination operand result in a #PF, vmread should
not call nested_vmx_succeed() to set rflags to specify success. Similar to as
done in for VMPTRST (See handle_vmptrst()).
"""

In addition, it will be appreciated if you would also submit kvm-unit-test that verifies this condition.

-Liran

> ---
> arch/x86/kvm/vmx/nested.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index 8edefdc9c0cb..c1ec9f25a417 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -4799,8 +4799,10 @@ static int handle_vmread(struct kvm_vcpu *vcpu)
> instr_info, true, len, &gva))
> return 1;
> /* _system ok, nested_vmx_check_permission has verified cpl=0 */
> - if (kvm_write_guest_virt_system(vcpu, gva, &value, len, &e))
> + if (kvm_write_guest_virt_system(vcpu, gva, &value, len, &e)) {
> kvm_inject_page_fault(vcpu, &e);
> + return 1;
> + }
> }
>
> return nested_vmx_succeed(vcpu);
> --
> 2.19.1
>

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