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authorPaul Mackerras <paulus@ozlabs.org>2018-08-20 09:05:45 +0300
committerBen Hutchings <ben@decadent.org.uk>2018-12-17 01:08:49 +0300
commitbd52aa398818e7ed7c6538f61cf3fbd3613af2b0 (patch)
tree74c88508b469db880d26484531b88ed8d6373338
parent6c1c9fe8444b382595ef52059419d53894452dc2 (diff)
downloadlinux-bd52aa398818e7ed7c6538f61cf3fbd3613af2b0.tar.xz
KVM: PPC: Book3S HV: Don't truncate HPTE index in xlate function
commit 46dec40fb741f00f1864580130779aeeaf24fb3d upstream. This fixes a bug which causes guest virtual addresses to get translated to guest real addresses incorrectly when the guest is using the HPT MMU and has more than 256GB of RAM, or more specifically has a HPT larger than 2GB. This has showed up in testing as a failure of the host to emulate doorbell instructions correctly on POWER9 for HPT guests with more than 256GB of RAM. The bug is that the HPTE index in kvmppc_mmu_book3s_64_hv_xlate() is stored as an int, and in forming the HPTE address, the index gets shifted left 4 bits as an int before being signed-extended to 64 bits. The simple fix is to make the variable a long int, matching the return type of kvmppc_hv_find_lock_hpte(), which is what calculates the index. Fixes: 697d3899dcb4 ("KVM: PPC: Implement MMIO emulation support for Book3S HV guests") Signed-off-by: Paul Mackerras <paulus@ozlabs.org> [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
-rw-r--r--arch/powerpc/kvm/book3s_64_mmu_hv.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index 68468d695f12..ccae6963d1cf 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -451,7 +451,7 @@ static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr,
unsigned long pp, key;
unsigned long v, gr;
unsigned long *hptep;
- int index;
+ long int index;
int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR);
/* Get SLB entry */