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| author | Paolo Bonzini <pbonzini@redhat.com> | 2017-07-24 18:54:38 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2017-07-26 18:57:45 +0200 |
| commit | a512177ef3bb92dbec8a96fe337b11c126bf9c91 (patch) | |
| tree | 6e141e2fb56dfd3c6f856d8e3d7e5bdcfae8aff3 | |
| parent | fdeaf7e3eb37c6dbc4b4ac97dbe1945d239eb788 (diff) | |
| download | linux-a512177ef3bb92dbec8a96fe337b11c126bf9c91.tar.gz linux-a512177ef3bb92dbec8a96fe337b11c126bf9c91.tar.bz2 linux-a512177ef3bb92dbec8a96fe337b11c126bf9c91.zip | |
KVM: x86: do mask out upper bits of PAE CR3
This reverts the change of commit f85c758dbee54cc3612a6e873ef7cecdb66ebee5,
as the behavior it modified was intended.
The VM is running in 32-bit PAE mode, and Table 4-7 of the Intel manual
says:
Table 4-7. Use of CR3 with PAE Paging
Bit Position(s) Contents
4:0 Ignored
31:5 Physical address of the 32-Byte aligned
page-directory-pointer table used for linear-address
translation
63:32 Ignored (these bits exist only on processors supporting
the Intel-64 architecture)
To placate the static checker, write the mask explicitly as an
unsigned long constant instead of using a 32-bit unsigned constant.
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: f85c758dbee54cc3612a6e873ef7cecdb66ebee5
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | arch/x86/kvm/x86.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 82a63c59f77b..6c97c82814c4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -597,8 +597,8 @@ bool pdptrs_changed(struct kvm_vcpu *vcpu) (unsigned long *)&vcpu->arch.regs_avail)) return true; - gfn = (kvm_read_cr3(vcpu) & ~31ul) >> PAGE_SHIFT; - offset = (kvm_read_cr3(vcpu) & ~31ul) & (PAGE_SIZE - 1); + gfn = (kvm_read_cr3(vcpu) & 0xffffffe0ul) >> PAGE_SHIFT; + offset = (kvm_read_cr3(vcpu) & 0xffffffe0ul) & (PAGE_SIZE - 1); r = kvm_read_nested_guest_page(vcpu, gfn, pdpte, offset, sizeof(pdpte), PFERR_USER_MASK | PFERR_WRITE_MASK); if (r < 0) |