qemu-patch-raspberry4/target-ppc/kvm.c
Alexander Graf fc87e18530 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 <agraf@suse.de>
2010-09-05 11:50:48 +02:00

399 lines
9.3 KiB
C

/*
* PowerPC implementation of KVM hooks
*
* Copyright IBM Corp. 2007
*
* Authors:
* Jerone Young <jyoung5@us.ibm.com>
* Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
* Hollis Blanchard <hollisb@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*
*/
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/kvm.h>
#include "qemu-common.h"
#include "qemu-timer.h"
#include "sysemu.h"
#include "kvm.h"
#include "kvm_ppc.h"
#include "cpu.h"
#include "device_tree.h"
//#define DEBUG_KVM
#ifdef DEBUG_KVM
#define dprintf(fmt, ...) \
do { fprintf(stderr, fmt, ## __VA_ARGS__); } while (0)
#else
#define dprintf(fmt, ...) \
do { } while (0)
#endif
static int cap_interrupt_unset = false;
static int cap_interrupt_level = false;
/* XXX We have a race condition where we actually have a level triggered
* interrupt, but the infrastructure can't expose that yet, so the guest
* takes but ignores it, goes to sleep and never gets notified that there's
* still an interrupt pending.
*
* As a quick workaround, let's just wake up again 20 ms after we injected
* an interrupt. That way we can assure that we're always reinjecting
* interrupts in case the guest swallowed them.
*/
static QEMUTimer *idle_timer;
static void kvm_kick_env(void *env)
{
qemu_cpu_kick(env);
}
int kvm_arch_init(KVMState *s, int smp_cpus)
{
#ifdef KVM_CAP_PPC_UNSET_IRQ
cap_interrupt_unset = kvm_check_extension(s, KVM_CAP_PPC_UNSET_IRQ);
#endif
#ifdef KVM_CAP_PPC_IRQ_LEVEL
cap_interrupt_level = kvm_check_extension(s, KVM_CAP_PPC_IRQ_LEVEL);
#endif
if (!cap_interrupt_level) {
fprintf(stderr, "KVM: Couldn't find level irq capability. Expect the "
"VM to stall at times!\n");
}
return 0;
}
int kvm_arch_init_vcpu(CPUState *cenv)
{
int ret = 0;
struct kvm_sregs sregs;
sregs.pvr = cenv->spr[SPR_PVR];
ret = kvm_vcpu_ioctl(cenv, KVM_SET_SREGS, &sregs);
idle_timer = qemu_new_timer(vm_clock, kvm_kick_env, cenv);
return ret;
}
void kvm_arch_reset_vcpu(CPUState *env)
{
}
int kvm_arch_put_registers(CPUState *env, int level)
{
struct kvm_regs regs;
int ret;
int i;
ret = kvm_vcpu_ioctl(env, KVM_GET_REGS, &regs);
if (ret < 0)
return ret;
regs.ctr = env->ctr;
regs.lr = env->lr;
regs.xer = env->xer;
regs.msr = env->msr;
regs.pc = env->nip;
regs.srr0 = env->spr[SPR_SRR0];
regs.srr1 = env->spr[SPR_SRR1];
regs.sprg0 = env->spr[SPR_SPRG0];
regs.sprg1 = env->spr[SPR_SPRG1];
regs.sprg2 = env->spr[SPR_SPRG2];
regs.sprg3 = env->spr[SPR_SPRG3];
regs.sprg4 = env->spr[SPR_SPRG4];
regs.sprg5 = env->spr[SPR_SPRG5];
regs.sprg6 = env->spr[SPR_SPRG6];
regs.sprg7 = env->spr[SPR_SPRG7];
for (i = 0;i < 32; i++)
regs.gpr[i] = env->gpr[i];
ret = kvm_vcpu_ioctl(env, KVM_SET_REGS, &regs);
if (ret < 0)
return ret;
return ret;
}
int kvm_arch_get_registers(CPUState *env)
{
struct kvm_regs regs;
struct kvm_sregs sregs;
uint32_t i, ret;
ret = kvm_vcpu_ioctl(env, KVM_GET_REGS, &regs);
if (ret < 0)
return ret;
ret = kvm_vcpu_ioctl(env, KVM_GET_SREGS, &sregs);
if (ret < 0)
return ret;
env->ctr = regs.ctr;
env->lr = regs.lr;
env->xer = regs.xer;
env->msr = regs.msr;
env->nip = regs.pc;
env->spr[SPR_SRR0] = regs.srr0;
env->spr[SPR_SRR1] = regs.srr1;
env->spr[SPR_SPRG0] = regs.sprg0;
env->spr[SPR_SPRG1] = regs.sprg1;
env->spr[SPR_SPRG2] = regs.sprg2;
env->spr[SPR_SPRG3] = regs.sprg3;
env->spr[SPR_SPRG4] = regs.sprg4;
env->spr[SPR_SPRG5] = regs.sprg5;
env->spr[SPR_SPRG6] = regs.sprg6;
env->spr[SPR_SPRG7] = regs.sprg7;
for (i = 0;i < 32; i++)
env->gpr[i] = regs.gpr[i];
#ifdef KVM_CAP_PPC_SEGSTATE
if (kvm_check_extension(env->kvm_state, KVM_CAP_PPC_SEGSTATE)) {
env->sdr1 = sregs.u.s.sdr1;
/* Sync SLB */
#ifdef TARGET_PPC64
for (i = 0; i < 64; i++) {
ppc_store_slb(env, sregs.u.s.ppc64.slb[i].slbe,
sregs.u.s.ppc64.slb[i].slbv);
}
#endif
/* Sync SRs */
for (i = 0; i < 16; i++) {
env->sr[i] = sregs.u.s.ppc32.sr[i];
}
/* Sync BATs */
for (i = 0; i < 8; i++) {
env->DBAT[0][i] = sregs.u.s.ppc32.dbat[i] & 0xffffffff;
env->DBAT[1][i] = sregs.u.s.ppc32.dbat[i] >> 32;
env->IBAT[0][i] = sregs.u.s.ppc32.ibat[i] & 0xffffffff;
env->IBAT[1][i] = sregs.u.s.ppc32.ibat[i] >> 32;
}
}
#endif
return 0;
}
int kvmppc_set_interrupt(CPUState *env, int irq, int level)
{
unsigned virq = level ? KVM_INTERRUPT_SET_LEVEL : KVM_INTERRUPT_UNSET;
if (irq != PPC_INTERRUPT_EXT) {
return 0;
}
if (!kvm_enabled() || !cap_interrupt_unset || !cap_interrupt_level) {
return 0;
}
kvm_vcpu_ioctl(env, KVM_INTERRUPT, &virq);
return 0;
}
#if defined(TARGET_PPCEMB)
#define PPC_INPUT_INT PPC40x_INPUT_INT
#elif defined(TARGET_PPC64)
#define PPC_INPUT_INT PPC970_INPUT_INT
#else
#define PPC_INPUT_INT PPC6xx_INPUT_INT
#endif
int kvm_arch_pre_run(CPUState *env, struct kvm_run *run)
{
int r;
unsigned irq;
/* PowerPC Qemu tracks the various core input pins (interrupt, critical
* interrupt, reset, etc) in PPC-specific env->irq_input_state. */
if (!cap_interrupt_level &&
run->ready_for_interrupt_injection &&
(env->interrupt_request & CPU_INTERRUPT_HARD) &&
(env->irq_input_state & (1<<PPC_INPUT_INT)))
{
/* For now KVM disregards the 'irq' argument. However, in the
* future KVM could cache it in-kernel to avoid a heavyweight exit
* when reading the UIC.
*/
irq = KVM_INTERRUPT_SET;
dprintf("injected interrupt %d\n", irq);
r = kvm_vcpu_ioctl(env, KVM_INTERRUPT, &irq);
if (r < 0)
printf("cpu %d fail inject %x\n", env->cpu_index, irq);
/* Always wake up soon in case the interrupt was level based */
qemu_mod_timer(idle_timer, qemu_get_clock(vm_clock) +
(get_ticks_per_sec() / 50));
}
/* We don't know if there are more interrupts pending after this. However,
* the guest will return to userspace in the course of handling this one
* anyways, so we will get a chance to deliver the rest. */
return 0;
}
int kvm_arch_post_run(CPUState *env, struct kvm_run *run)
{
return 0;
}
int kvm_arch_process_irqchip_events(CPUState *env)
{
return 0;
}
static int kvmppc_handle_halt(CPUState *env)
{
if (!(env->interrupt_request & CPU_INTERRUPT_HARD) && (msr_ee)) {
env->halted = 1;
env->exception_index = EXCP_HLT;
}
return 1;
}
/* map dcr access to existing qemu dcr emulation */
static int kvmppc_handle_dcr_read(CPUState *env, uint32_t dcrn, uint32_t *data)
{
if (ppc_dcr_read(env->dcr_env, dcrn, data) < 0)
fprintf(stderr, "Read to unhandled DCR (0x%x)\n", dcrn);
return 1;
}
static int kvmppc_handle_dcr_write(CPUState *env, uint32_t dcrn, uint32_t data)
{
if (ppc_dcr_write(env->dcr_env, dcrn, data) < 0)
fprintf(stderr, "Write to unhandled DCR (0x%x)\n", dcrn);
return 1;
}
int kvm_arch_handle_exit(CPUState *env, struct kvm_run *run)
{
int ret = 0;
switch (run->exit_reason) {
case KVM_EXIT_DCR:
if (run->dcr.is_write) {
dprintf("handle dcr write\n");
ret = kvmppc_handle_dcr_write(env, run->dcr.dcrn, run->dcr.data);
} else {
dprintf("handle dcr read\n");
ret = kvmppc_handle_dcr_read(env, run->dcr.dcrn, &run->dcr.data);
}
break;
case KVM_EXIT_HLT:
dprintf("handle halt\n");
ret = kvmppc_handle_halt(env);
break;
}
return ret;
}
static int read_cpuinfo(const char *field, char *value, int len)
{
FILE *f;
int ret = -1;
int field_len = strlen(field);
char line[512];
f = fopen("/proc/cpuinfo", "r");
if (!f) {
return -1;
}
do {
if(!fgets(line, sizeof(line), f)) {
break;
}
if (!strncmp(line, field, field_len)) {
strncpy(value, line, len);
ret = 0;
break;
}
} while(*line);
fclose(f);
return ret;
}
uint32_t kvmppc_get_tbfreq(void)
{
char line[512];
char *ns;
uint32_t retval = get_ticks_per_sec();
if (read_cpuinfo("timebase", line, sizeof(line))) {
return retval;
}
if (!(ns = strchr(line, ':'))) {
return retval;
}
ns++;
retval = atoi(ns);
return retval;
}
int kvmppc_get_hypercall(CPUState *env, uint8_t *buf, int buf_len)
{
uint32_t *hc = (uint32_t*)buf;
#ifdef KVM_CAP_PPC_GET_PVINFO
struct kvm_ppc_pvinfo pvinfo;
if (kvm_check_extension(env->kvm_state, KVM_CAP_PPC_GET_PVINFO) &&
!kvm_vm_ioctl(env->kvm_state, KVM_PPC_GET_PVINFO, &pvinfo)) {
memcpy(buf, pvinfo.hcall, buf_len);
return 0;
}
#endif
/*
* Fallback to always fail hypercalls:
*
* li r3, -1
* nop
* nop
* nop
*/
hc[0] = 0x3860ffff;
hc[1] = 0x60000000;
hc[2] = 0x60000000;
hc[3] = 0x60000000;
return 0;
}
bool kvm_arch_stop_on_emulation_error(CPUState *env)
{
return true;
}