Merge tag 'kvm-arm-for-5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm...

[linux-2.6-microblaze.git] / arch / x86 / kvm / mmu.c

diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 6248c39..15d2c06 100644 (file)
--- 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"
@@ -5606,14 +5603,18 @@ 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;