lkml.org 
[lkml]   [2018]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v4 01/14] X86/nVMX: handle_vmon: Read 4 bytes from guest memory
From
Date
On 03.12.18 10:30, KarimAllah Ahmed wrote:
> Read the data directly from guest memory instead of the map->read->unmap
> sequence. This also avoids using kvm_vcpu_gpa_to_page() and kmap() which
> assumes that there is a "struct page" for guest memory.
>
> Suggested-by: Jim Mattson <jmattson@google.com>
> Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de>
> Reviewed-by: Jim Mattson <jmattson@google.com>
>
> ---
> v1 -> v2:
> - Massage commit message a bit.
> ---
> arch/x86/kvm/vmx.c | 14 +++-----------
> 1 file changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> index 02edd99..b84f230 100644
> --- a/arch/x86/kvm/vmx.c
> +++ b/arch/x86/kvm/vmx.c
> @@ -8358,7 +8358,7 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
> {
> int ret;
> gpa_t vmptr;
> - struct page *page;
> + uint32_t revision;
> struct vcpu_vmx *vmx = to_vmx(vcpu);
> const u64 VMXON_NEEDED_FEATURES = FEATURE_CONTROL_LOCKED
> | FEATURE_CONTROL_VMXON_ENABLED_OUTSIDE_SMX;
> @@ -8407,18 +8407,10 @@ static int handle_vmon(struct kvm_vcpu *vcpu)
> if (!PAGE_ALIGNED(vmptr) || (vmptr >> cpuid_maxphyaddr(vcpu)))
> return nested_vmx_failInvalid(vcpu);
>
> - page = kvm_vcpu_gpa_to_page(vcpu, vmptr);
> - if (is_error_page(page))
> + if (kvm_read_guest(vcpu->kvm, vmptr, &revision, sizeof(revision)) ||
> + revision != VMCS12_REVISION)
> return nested_vmx_failInvalid(vcpu);
>
> - if (*(u32 *)kmap(page) != VMCS12_REVISION) {
> - kunmap(page);
> - kvm_release_page_clean(page);
> - return nested_vmx_failInvalid(vcpu);
> - }
> - kunmap(page);
> - kvm_release_page_clean(page);
> -
> vmx->nested.vmxon_ptr = vmptr;
> ret = enter_vmx_operation(vcpu);
> if (ret)
>

Reviewed-by: David Hildenbrand <david@redhat.com>

--

Thanks,

David / dhildenb

\
 
 \ /
  Last update: 2018-12-03 13:49    [W:0.228 / U:33.776 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site