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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2018-01-12 13:37:13 +1100 |
|---|---|---|
| committer | Paul Mackerras <paulus@ozlabs.org> | 2018-01-19 12:10:21 +1100 |
| commit | 2267ea7661798a42f0da648a2970e2a03f4bc370 (patch) | |
| tree | c81a43b275313a69d33b1f8276255739114863d0 | |
| parent | bf4159da4751ab8eea43ca6e7c49193dbce8398c (diff) | |
| download | linux-2267ea7661798a42f0da648a2970e2a03f4bc370.tar.gz linux-2267ea7661798a42f0da648a2970e2a03f4bc370.tar.bz2 linux-2267ea7661798a42f0da648a2970e2a03f4bc370.zip | |
KVM: PPC: Book3S HV: Don't use existing "prodded" flag for XIVE escalations
The prodded flag is only cleared at the beginning of H_CEDE,
so every time we have an escalation, we will cause the *next*
H_CEDE to return immediately.
Instead use a dedicated "irq_pending" flag to indicate that
a guest interrupt is pending for the VCPU. We don't reuse the
existing exception bitmap so as to avoid expensive atomic ops.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
| -rw-r--r-- | arch/powerpc/include/asm/kvm_host.h | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/asm-offsets.c | 1 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_rmhandlers.S | 10 | ||||
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive.c | 3 |
5 files changed, 14 insertions, 3 deletions
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h index 3aa5b577cd60..bfe51356af5e 100644 --- a/arch/powerpc/include/asm/kvm_host.h +++ b/arch/powerpc/include/asm/kvm_host.h @@ -709,6 +709,7 @@ struct kvm_vcpu_arch { u8 ceded; u8 prodded; u8 doorbell_request; + u8 irq_pending; /* Used by XIVE to signal pending guest irqs */ u32 last_inst; struct swait_queue_head *wqp; diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 6b958414b4e0..825089cf3e23 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -514,6 +514,7 @@ int main(void) OFFSET(VCPU_PENDING_EXC, kvm_vcpu, arch.pending_exceptions); OFFSET(VCPU_CEDED, kvm_vcpu, arch.ceded); OFFSET(VCPU_PRODDED, kvm_vcpu, arch.prodded); + OFFSET(VCPU_IRQ_PENDING, kvm_vcpu, arch.irq_pending); OFFSET(VCPU_DBELL_REQ, kvm_vcpu, arch.doorbell_request); OFFSET(VCPU_MMCR, kvm_vcpu, arch.mmcr); OFFSET(VCPU_PMC, kvm_vcpu, arch.pmc); diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 76cf48051eb3..e5f81fc108e0 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -2999,7 +2999,7 @@ static inline bool xive_interrupt_pending(struct kvm_vcpu *vcpu) { if (!xive_enabled()) return false; - return vcpu->arch.xive_saved_state.pipr < + return vcpu->arch.irq_pending || vcpu->arch.xive_saved_state.pipr < vcpu->arch.xive_saved_state.cppr; } #else diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index 7daf21be33d0..34dbab7deb39 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -1035,6 +1035,16 @@ ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300) li r9, 1 stw r9, VCPU_XIVE_PUSHED(r4) eieio + + /* + * We clear the irq_pending flag. There is a small chance of a + * race vs. the escalation interrupt happening on another + * processor setting it again, but the only consequence is to + * cause a spurrious wakeup on the next H_CEDE which is not an + * issue. + */ + li r0,0 + stb r0, VCPU_IRQ_PENDING(r4) no_xive: #endif /* CONFIG_KVM_XICS */ diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c index a102efeabf05..eef9ccafdc09 100644 --- a/arch/powerpc/kvm/book3s_xive.c +++ b/arch/powerpc/kvm/book3s_xive.c @@ -84,8 +84,7 @@ static irqreturn_t xive_esc_irq(int irq, void *data) { struct kvm_vcpu *vcpu = data; - /* We use the existing H_PROD mechanism to wake up the target */ - vcpu->arch.prodded = 1; + vcpu->arch.irq_pending = 1; smp_mb(); if (vcpu->arch.ceded) kvmppc_fast_vcpu_kick(vcpu); |