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From 4f50d1fdd77ea1e2db084b8282ed81a7d6c87a26 Mon Sep 17 00:00:00 2001
From: Michael Neuling <mikey@neuling.org>
Date: Thu, 20 Jun 2019 16:00:40 +1000
Subject: [PATCH] KVM: PPC: Book3S HV: Fix CR0 setting in TM emulation

References: bsc#1061840
Patch-mainline: v5.3-rc1
Git-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>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
 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 008285058f9b..d23a0131b016 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.cr = (vcpu->arch.cr & 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.cr = (vcpu->arch.cr & 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.cr = (vcpu->arch.cr & 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;
 	}
-- 
2.22.0