summaryrefslogtreecommitdiffstats
path: root/arch/x86/kvm/mmu.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kvm/mmu.c')
-rw-r--r--arch/x86/kvm/mmu.c21
1 files changed, 11 insertions, 10 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 1e9ba81accba..98f6e4f88b04 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* Kernel-based Virtual Machine driver for Linux
*
@@ -12,10 +13,6 @@
* Authors:
* Yaniv Kamay <yaniv@qumranet.com>
* Avi Kivity <avi@qumranet.com>
- *
- * This work is licensed under the terms of the GNU GPL, version 2. See
- * the COPYING file in the top-level directory.
- *
*/
#include "irq.h"
@@ -5602,14 +5599,18 @@ static int alloc_mmu_pages(struct kvm_vcpu *vcpu)
struct page *page;
int i;
- if (tdp_enabled)
- 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.
+ * 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;
+
page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_DMA32);
if (!page)
return -ENOMEM;