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authorNicholas Piggin <npiggin@gmail.com>2021-08-12 02:00:43 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2021-08-25 16:37:18 +1000
commit1782663897945a5cf28e564ba5eed730098e9aa4 (patch)
tree82ddfdaa26a815e27a79cad06c51c0a29e5c4f14 /arch/powerpc/include
parentf2e29db156523bf08a0524e0f4306a641912c6d9 (diff)
downloadlinux-1782663897945a5cf28e564ba5eed730098e9aa4.tar.bz2
KVM: PPC: Book3S HV Nested: Reflect guest PMU in-use to L0 when guest SPRs are live
After the L1 saves its PMU SPRs but before loading the L2's PMU SPRs, switch the pmcregs_in_use field in the L1 lppaca to the value advertised by the L2 in its VPA. On the way out of the L2, set it back after saving the L2 PMU registers (if they were in-use). This transfers the PMU liveness indication between the L1 and L2 at the points where the registers are not live. This fixes the nested HV bug for which a workaround was added to the L0 HV by commit 63279eeb7f93a ("KVM: PPC: Book3S HV: Always save guest pmu for guest capable of nesting"), which explains the problem in detail. That workaround is no longer required for guests that include this bug fix. Fixes: 360cae313702 ("KVM: PPC: Book3S HV: Nested guest entry via hypercall") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Reviewed-by: Fabiano Rosas <farosas@linux.ibm.com> Link: https://lore.kernel.org/r/20210811160134.904987-10-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/include')
-rw-r--r--arch/powerpc/include/asm/pmc.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pmc.h b/arch/powerpc/include/asm/pmc.h
index c6bbe9778d3c..3c09109e708e 100644
--- a/arch/powerpc/include/asm/pmc.h
+++ b/arch/powerpc/include/asm/pmc.h
@@ -34,6 +34,13 @@ static inline void ppc_set_pmu_inuse(int inuse)
#endif
}
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+static inline int ppc_get_pmu_inuse(void)
+{
+ return get_paca()->pmcregs_in_use;
+}
+#endif
+
extern void power4_enable_pmcs(void);
#else /* CONFIG_PPC64 */