From: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
To: benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au,
npiggin@gmail.com, christophe.leroy@c-s.fr,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
kvm-ppc@vger.kernel.org
Subject: [PATCH] powerpc: fix 32-bit KVM-PR lockup and panic with MacOS guest
Date: Fri, 8 Feb 2019 14:33:19 +0000 [thread overview]
Message-ID: <20190208143319.11980-1-mark.cave-ayland@ilande.co.uk> (raw)
Commit 8792468da5e1 "powerpc: Add the ability to save FPU without giving it up"
unexpectedly removed the MSR_FE0 and MSR_FE1 bits from the bitmask used to
update the MSR of the previous thread in __giveup_fpu() causing a KVM-PR MacOS
guest to lockup and panic the kernel.
Reinstate these bits to the MSR bitmask to enable MacOS guests to run under
32-bit KVM-PR once again without issue.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
---
arch/powerpc/kernel/process.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index ce393df243aa..71bad4b6f80d 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -176,7 +176,7 @@ static void __giveup_fpu(struct task_struct *tsk)
save_fpu(tsk);
msr = tsk->thread.regs->msr;
- msr &= ~MSR_FP;
+ msr &= ~(MSR_FP|MSR_FE0|MSR_FE1);
#ifdef CONFIG_VSX
if (cpu_has_feature(CPU_FTR_VSX))
msr &= ~MSR_VSX;
--
2.11.0
next reply other threads:[~2019-02-08 14:43 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-08 14:33 Mark Cave-Ayland [this message]
2019-02-08 14:45 ` [PATCH] powerpc: fix 32-bit KVM-PR lockup and panic with MacOS guest Christophe Leroy
2019-02-08 14:51 ` Mark Cave-Ayland
2019-02-11 0:30 ` Benjamin Herrenschmidt
2019-02-11 21:39 ` Mark Cave-Ayland
2019-02-19 4:55 ` Michael Ellerman
2019-02-19 8:15 ` Mark Cave-Ayland
2019-02-19 4:20 ` Michael Ellerman
2019-02-19 7:55 ` Mark Cave-Ayland
2019-02-20 12:41 ` Michael Ellerman
2019-02-22 9:47 ` Michael Ellerman
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