[PATCH 4.19 157/190] KVM: PPC: Book3S HV: Fix CR0 setting in TM emulation

Greg Kroah-Hartman
2019-09-13T13:18:53Z

[ Upstream commit 3fefd1cd95df04da67c83c1cb93b663f04b3324f ]

When emulating tsr, treclaim and trechkpt, we incorrectly set CR0. The
code currently sets:
CR0 <- 00 || MSR[TS]
but according to the ISA it should be:
CR0 <- 0 || MSR[TS] || 0

This fixes the bit shift to put the bits in the correct location.

This is a data integrity issue as CR0 is corrupted.

Fixes: 4bb3c7a0208f ("KVM: PPC: Book3S HV: Work around transactional memory bugs in POWER9")
Cc: stable@vger.kernel.org # v4.17+
Tested-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/kvm/book3s_hv_tm.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_hv_tm.c b/arch/powerpc/kvm/book3s_hv_tm.c
index 888e2609e3f15..31cd0f327c8a2 100644
--- a/arch/powerpc/kvm/book3s_hv_tm.c
+++ b/arch/powerpc/kvm/book3s_hv_tm.c
@@ -131,7 +131,7 @@ int kvmhv_p9_tm_emulation(struct kvm_vcpu *vcpu)
}
/* Set CR0 to indicate previous transactional state */
vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
- (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 28);
+ (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
/* L=1 => tresume, L=0 => tsuspend */
if (instr & (1 << 21)) {
if (MSR_TM_SUSPENDED(msr))
@@ -175,7 +175,7 @@ int kvmhv_p9_tm_emulation(struct kvm_vcpu *vcpu)

/* Set CR0 to indicate previous transactional state */
vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
- (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 28);
+ (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
vcpu->arch.shregs.msr &= ~MSR_TS_MASK;
return RESUME_GUEST;

@@ -205,7 +205,7 @@ int kvmhv_p9_tm_emulation(struct kvm_vcpu *vcpu)

/* Set CR0 to indicate previous transactional state */
vcpu->arch.regs.ccr = (vcpu->arch.regs.ccr & 0x0fffffff) |
- (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 28);
+ (((msr & MSR_TS_MASK) >> MSR_TS_S_LG) << 29);
vcpu->arch.shregs.msr = msr | MSR_TS_S;
return RESUME_GUEST;
}
--
2.20.1