[PATCH v2 08/11] powerpc: Mark writes registering ipi to host cpu through kvm and polling
From: Rohan McLure <hidden>
Date: 2023-05-10 03:39:25
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Mark writes to hypervisor ipi state so that KCSAN recognises these
asynchronous issue of kvmppc_{set,clear}_host_ipi to be intended, with
atomic writes. Mark asynchronous polls to this variable in
kvm_ppc_read_one_intr().
Signed-off-by: Rohan McLure <redacted>
---
v2: Add read-side annotations to both polling locations in
kvm_ppc_read_one_intr().
---
arch/powerpc/include/asm/kvm_ppc.h | 4 ++--
arch/powerpc/kvm/book3s_hv_builtin.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index bc57d058ad5b..d701df006c08 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h@@ -548,12 +548,12 @@ static inline void kvmppc_set_host_ipi(int cpu) * pairs with the barrier in kvmppc_clear_host_ipi() */ smp_mb(); - paca_ptrs[cpu]->kvm_hstate.host_ipi = 1; + WRITE_ONCE(paca_ptrs[cpu]->kvm_hstate.host_ipi, 1); } static inline void kvmppc_clear_host_ipi(int cpu) { - paca_ptrs[cpu]->kvm_hstate.host_ipi = 0; + WRITE_ONCE(paca_ptrs[cpu]->kvm_hstate.host_ipi, 0); /* * order clearing of host_ipi flag vs. processing of IPI messages *
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c
index da85f046377a..0f5b021fa559 100644
--- a/arch/powerpc/kvm/book3s_hv_builtin.c
+++ b/arch/powerpc/kvm/book3s_hv_builtin.c@@ -406,7 +406,7 @@ static long kvmppc_read_one_intr(bool *again) return 1; /* see if a host IPI is pending */ - host_ipi = local_paca->kvm_hstate.host_ipi; + host_ipi = READ_ONCE(local_paca->kvm_hstate.host_ipi); if (host_ipi) return 1;
@@ -466,7 +466,7 @@ static long kvmppc_read_one_intr(bool *again) * meantime. If it's clear, we bounce the interrupt to the * guest */ - host_ipi = local_paca->kvm_hstate.host_ipi; + host_ipi = READ_ONCE(local_paca->kvm_hstate.host_ipi); if (unlikely(host_ipi != 0)) { /* We raced with the host, * we need to resend that IPI, bummer
--
2.37.2