lkml.org 
[lkml]   [2022]   [Jun]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 1/1] KVM: x86/mmu: Set memory encryption "value", not "mask", in shadow PDPTRs
From
On 6/8/22 03:20, Yuan Yao wrote:
> Assign shadow_me_value, not shadow_me_mask, to PAE root entries,
> a.k.a. shadow PDPTRs, when host memory encryption is supported. The
> "mask" is the set of all possible memory encryption bits, e.g. MKTME
> KeyIDs, whereas "value" holds the actual value that needs to be
> stuffed into host page tables.
>
> Using shadow_me_mask results in a failed VM-Entry due to setting
> reserved PA bits in the PDPTRs, and ultimately causes an OOPS due to
> physical addresses with non-zero MKTME bits sending to_shadow_page()
> into the weeds:
>
> set kvm_intel.dump_invalid_vmcs=1 to dump internal KVM state.
> BUG: unable to handle page fault for address: ffd43f00063049e8
> PGD 86dfd8067 P4D 0
> Oops: 0000 [#1] PREEMPT SMP
> RIP: 0010:mmu_free_root_page+0x3c/0x90 [kvm]
> kvm_mmu_free_roots+0xd1/0x200 [kvm]
> __kvm_mmu_unload+0x29/0x70 [kvm]
> kvm_mmu_unload+0x13/0x20 [kvm]
> kvm_arch_destroy_vm+0x8a/0x190 [kvm]
> kvm_put_kvm+0x197/0x2d0 [kvm]
> kvm_vm_release+0x21/0x30 [kvm]
> __fput+0x8e/0x260
> ____fput+0xe/0x10
> task_work_run+0x6f/0xb0
> do_exit+0x327/0xa90
> do_group_exit+0x35/0xa0
> get_signal+0x911/0x930
> arch_do_signal_or_restart+0x37/0x720
> exit_to_user_mode_prepare+0xb2/0x140
> syscall_exit_to_user_mode+0x16/0x30
> do_syscall_64+0x4e/0x90
> entry_SYSCALL_64_after_hwframe+0x44/0xae
>
> Fixes: e54f1ff244ac ("KVM: x86/mmu: Add shadow_me_value and repurpose shadow_me_mask")
> Signed-off-by: Yuan Yao <yuan.yao@intel.com>
> Reviewed-by: Kai Huang <kai.huang@intel.com>
> ---
> arch/x86/kvm/mmu/mmu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index efe5a3dca1e0..6bd144f1e60c 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -3411,7 +3411,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu)
> root = mmu_alloc_root(vcpu, i << (30 - PAGE_SHIFT),
> i << 30, PT32_ROOT_LEVEL, true);
> mmu->pae_root[i] = root | PT_PRESENT_MASK |
> - shadow_me_mask;
> + shadow_me_value;
> }
> mmu->root.hpa = __pa(mmu->pae_root);
> } else {

Queued, thanks.

Paolo

\
 
 \ /
  Last update: 2022-06-08 14:43    [W:0.075 / U:0.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site