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authorSuraj Jitindar Singh2019-07-03 11:20:21 +1000
committerMichael Ellerman2019-07-15 12:41:26 +1000
commit28d2a6e6684d9851905f379816d8a4d03587ed94 (patch)
treeda6632fc1ab2cbafe3c4d695d7a68422173e2a96 /arch
parent63279eeb7f93abb1692573c26f1e038e1a87358b (diff)
powerpc/pmu: Set pmcregs_in_use in paca when running as LPAR
The ability to run nested guests under KVM means that a guest can also act as a hypervisor for it's own nested guest. Currently ppc_set_pmu_inuse() assumes that either FW_FEATURE_LPAR is set, indicating a guest environment, and so sets the pmcregs_in_use flag in the lppaca, or that it isn't set, indicating a hypervisor environment, and so sets the pmcregs_in_use flag in the paca. The pmcregs_in_use flag in the lppaca is used to communicate this information to a hypervisor and so must be set in a guest environment. The pmcregs_in_use flag in the paca is used by KVM code to determine whether the host state of the performance monitoring unit (PMU) must be saved and restored when running a guest. Thus when a guest also acts as a hypervisor it must set this bit in both places since it needs to ensure both that the real hypervisor saves it's PMU registers when it runs (requires pmcregs_in_use flag in lppaca), and that it saves it's own PMU registers when running a nested guest (requires pmcregs_in_use flag in paca). Modify ppc_set_pmu_inuse() so that the pmcregs_in_use bit is set in both the lppaca and the paca when a guest (LPAR) is running with the capability of running it's own guests (CONFIG_KVM_BOOK3S_HV_POSSIBLE). Fixes: 95a6432ce903 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20190703012022.15644-2-sjitindarsingh@gmail.com
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/include/asm/pmc.h5
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/pmc.h b/arch/powerpc/include/asm/pmc.h
index dc9a1ca70edf..c6bbe9778d3c 100644
--- a/arch/powerpc/include/asm/pmc.h
+++ b/arch/powerpc/include/asm/pmc.h
@@ -27,11 +27,10 @@ static inline void ppc_set_pmu_inuse(int inuse)
#ifdef CONFIG_PPC_PSERIES
get_lppaca()->pmcregs_in_use = inuse;
#endif
- } else {
+ }
#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
- get_paca()->pmcregs_in_use = inuse;
+ get_paca()->pmcregs_in_use = inuse;
#endif
- }
#endif
}