| Message ID | 1500915555-34207-1-git-send-email-pbonzini@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2017-07-24 18:59+0200, Paolo Bonzini: > 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> > --- Thanks for catching this, Reviewed-by: Radim Krčmář <rkrcmar@redhat.com> > 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) > -- > 1.8.3.1 >
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)
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> --- arch/x86/kvm/x86.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)