On 07/07/2017 01:33, Jim Mattson wrote:
> Allow the L1 guest to specify the last page of addressable guest
> physical memory for an L2 MSR permission bitmap. Also remove the
> vmcs12_read_any() check that should never fail.
>
> Fixes: 3af18d9c5fe95 ("KVM: nVMX: Prepare for using hardware MSR bitmap")
> Signed-off-by: Jim Mattson <jmattson@xxxxxxxxxx>
> ---
> arch/x86/kvm/vmx.c | 17 ++++++-----------
> 1 file changed, 6 insertions(+), 11 deletions(-)
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index f03dcd744557..9bca5a59d65a 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -4631,6 +4631,11 @@ static bool guest_state_valid(struct kvm_vcpu *vcpu)
> return true;
> }
>
> +static bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
> +{
> + return PAGE_ALIGNED(gpa) && !(gpa >> cpuid_maxphyaddr(vcpu));
> +}
> +
> static int init_rmode_tss(struct kvm *kvm)
> {
> gfn_t fn;
> @@ -9587,20 +9592,10 @@ static int nested_vmx_check_io_bitmap_controls(struct kvm_vcpu *vcpu,
> static int nested_vmx_check_msr_bitmap_controls(struct kvm_vcpu *vcpu,
> struct vmcs12 *vmcs12)
> {
> - int maxphyaddr;
> - u64 addr;
> -
> if (!nested_cpu_has(vmcs12, CPU_BASED_USE_MSR_BITMAPS))
> return 0;
>
> - if (vmcs12_read_any(vcpu, MSR_BITMAP, &addr)) {
> - WARN_ON(1);
> - return -EINVAL;
> - }
> - maxphyaddr = cpuid_maxphyaddr(vcpu);
> -
> - if (!PAGE_ALIGNED(vmcs12->msr_bitmap) ||
> - ((addr + PAGE_SIZE) >> maxphyaddr))
> + if (!page_address_valid(vcpu, vmcs12->msr_bitmap))
> return -EINVAL;
>
> return 0;
>
