On Thu, 2021-08-19 at 18:43 +0200, Paolo Bonzini wrote:
> On 18/08/21 18:55, Wei Huang wrote:
> > This patch set adds 5-level page table support for AMD SVM. When the
> > 5-level page table is enabled on host OS, the nested page table for guest
> > VMs will use the same format as host OS (i.e. 5-level NPT). These patches
> > were tested with various combination of different settings and test cases
> > (nested/regular VMs, AMD64/i686 kernels, kvm-unit-tests, etc.)
> >
> > v2->v3:
> > * Change the way of building root_hpa by following the existing flow (Sean)
> >
> > v1->v2:
> > * Remove v1's arch-specific get_tdp_level() and add a new parameter,
> > tdp_forced_root_level, to allow forced TDP level (Sean)
> > * Add additional comment on tdp_root table chaining trick and change the
> > PML root table allocation code (Sean)
> > * Revise Patch 1's commit msg (Sean and Jim)
> >
> > Thanks,
> > -Wei
> >
> > Wei Huang (3):
> > KVM: x86: Allow CPU to force vendor-specific TDP level
> > KVM: x86: Handle the case of 5-level shadow page table
> > KVM: SVM: Add 5-level page table support for SVM
> >
> > arch/x86/include/asm/kvm_host.h | 6 ++--
> > arch/x86/kvm/mmu/mmu.c | 56 ++++++++++++++++++++++-----------
> > arch/x86/kvm/svm/svm.c | 13 ++++----
> > arch/x86/kvm/vmx/vmx.c | 3 +-
> > 4 files changed, 49 insertions(+), 29 deletions(-)
> >
>
> Queued, thanks, with NULL initializations according to Tom's review.
>
> Paolo
>
Hi,
Yesterday while testing my SMM patches, I noticed a minor issue:
It seems that this patchset breaks my 32 bit nested VM testcase with NPT=0.
This hack makes it work again for me (I don't yet use TDP mmu).
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index caa3f9aee7d1..c25e0d40a620 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3562,7 +3562,7 @@ static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
mmu->shadow_root_level < PT64_ROOT_4LEVEL)
return 0;
- if (mmu->pae_root && mmu->pml4_root && mmu->pml5_root)
+ if (mmu->pae_root && mmu->pml4_root)
return 0;
/*
Best regards,
Maxim Levitsky
