forked from Minki/linux
KVM: x86/mmu: Allocate PAE root array when using SVM's 32-bit NPT
SVM's Nested Page Tables (NPT) reuses x86 paging for the host-controlled
page walk. For 32-bit KVM, this means PAE paging is used even when TDP
is enabled, i.e. the PAE root array needs to be allocated.
Fixes: ee6268ba3a
("KVM: x86: Skip pae_root shadow allocation if tdp enabled")
Cc: stable@vger.kernel.org
Reported-by: Jiri Palecek <jpalecek@web.de>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
parent
6ca00dfafd
commit
b6b80c78af
@ -5602,14 +5602,18 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
|
||||
struct page *page;
|
||||
int i;
|
||||
|
||||
if (tdp_enabled)
|
||||
/*
|
||||
* When using PAE paging, the four PDPTEs are treated as 'root' pages,
|
||||
* while the PDP table is a per-vCPU construct that's allocated at MMU
|
||||
* creation. When emulating 32-bit mode, cr3 is only 32 bits even on
|
||||
* x86_64. Therefore we need to allocate the PDP table in the first
|
||||
* 4GB of memory, which happens to fit the DMA32 zone. Except for
|
||||
* SVM's 32-bit NPT support, TDP paging doesn't use PAE paging and can
|
||||
* skip allocating the PDP table.
|
||||
*/
|
||||
if (tdp_enabled && kvm_x86_ops->get_tdp_level(vcpu) > PT32E_ROOT_LEVEL)
|
||||
return 0;
|
||||
|
||||
/*
|
||||
* When emulating 32-bit mode, cr3 is only 32 bits even on x86_64.
|
||||
* Therefore we need to allocate shadow page tables in the first
|
||||
* 4GB of memory, which happens to fit the DMA32 zone.
|
||||
*/
|
||||
page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32);
|
||||
if (!page)
|
||||
return -ENOMEM;
|
||||
|
Loading…
Reference in New Issue
Block a user