From fc87e185302a96c2675a1c3a86ca47c6a2d657ff Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Mon, 30 Aug 2010 13:49:15 +0200 Subject: KVM: PPC: Add level based interrupt logic KVM on PowerPC used to have completely broken interrupt logic. Usually, interrupts work by having a PIC that pulls a line up/down, so the CPU knows that an interrupt is active. This line stays active until some action is done to the PIC to release the line. On KVM for PPC, we just checked if there was an interrupt pending and pulled a line in the kernel module. We never released it though, hoping that kernel space would just declare an interrupt as released when injected - which is wrong. To fix this, we need to completely redesign the interrupt injection logic. Whenever an interrupt line gets triggered, we need to notify kernel space that the line is up. Whenever it gets released, we do the same. This way we can assure that the interrupt state is always known to kernel space. This fixes random stalls in KVM guests on PowerPC that were waiting for an interrupt while everyone else thought they received it already. Signed-off-by: Alexander Graf --- hw/ppc.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'hw/ppc.c') diff --git a/hw/ppc.c b/hw/ppc.c index 2a77eb9bff..55e380844c 100644 --- a/hw/ppc.c +++ b/hw/ppc.c @@ -28,6 +28,8 @@ #include "nvram.h" #include "qemu-log.h" #include "loader.h" +#include "kvm.h" +#include "kvm_ppc.h" //#define PPC_DEBUG_IRQ //#define PPC_DEBUG_TB @@ -50,6 +52,8 @@ static void cpu_ppc_tb_start (CPUState *env); static void ppc_set_irq (CPUState *env, int n_IRQ, int level) { + unsigned int old_pending = env->pending_interrupts; + if (level) { env->pending_interrupts |= 1 << n_IRQ; cpu_interrupt(env, CPU_INTERRUPT_HARD); @@ -58,6 +62,13 @@ static void ppc_set_irq (CPUState *env, int n_IRQ, int level) if (env->pending_interrupts == 0) cpu_reset_interrupt(env, CPU_INTERRUPT_HARD); } + + if (old_pending != env->pending_interrupts) { +#ifdef CONFIG_KVM + kvmppc_set_interrupt(env, n_IRQ, level); +#endif + } + LOG_IRQ("%s: %p n_IRQ %d level %d => pending %08" PRIx32 "req %08x\n", __func__, env, n_IRQ, level, env->pending_interrupts, env->interrupt_request); -- cgit v1.2.3