linux-kernel - [RESEND PATCH 2/3] kvm, tdp: calculate correct base gfn for non-DIR level

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Message-ID: <4BFCE059.60502@cn.fujitsu.com>
Date:	Wed, 26 May 2010 16:48:25 +0800
From:	Lai Jiangshan <laijs@...fujitsu.com>
To:	Marcelo Tosatti <mtosatti@...hat.com>
CC:	Avi Kivity <avi@...hat.com>, LKML <linux-kernel@...r.kernel.org>,
	kvm@...r.kernel.org
Subject: [RESEND PATCH 2/3]  kvm, tdp: calculate correct base gfn for non-DIR
 level


In Document/kvm/mmu.txt:
  gfn:
    Either the guest page table containing the translations shadowed by this
    page, or the base page frame for linear translations. See role.direct.

But in __direct_map(), the base gfn calculation is incorrect,
it does not calculate correctly when level=3 or 4.

Reported-by: Marcelo Tosatti <mtosatti@...hat.com>
Signed-off-by: Lai Jiangshan <laijs@...fujitsu.com>
---
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a5c6719..6986a6f 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -1955,7 +1956,10 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
 		}
 
 		if (*iterator.sptep == shadow_trap_nonpresent_pte) {
-			pseudo_gfn = (iterator.addr & PT64_DIR_BASE_ADDR_MASK) >> PAGE_SHIFT;
+			u64 base_addr = iterator.addr;
+
+			base_addr &= PT64_LVL_ADDR_MASK(iterator.level);
+			pseudo_gfn = base_addr >> PAGE_SHIFT;
 			sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
 					      iterator.level - 1,
 					      1, ACC_ALL, iterator.sptep);




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