[PATCH] kvm-userspace: Make PC speaker emulation aware of in-kernel PIT

Jan Kiszka
2009-04-23T20:24:08Z

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When using the in-kernel PIT the speaker emulation has to synchronize
the PIT state with KVM. Enhance the existing speaker sound device and
allow it to take over port 0x61 by using KVM_CREATE_PIT_NOSPKR when
available. This unbreaks -soundhw pcspk in KVM mode.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

libkvm/libkvm-x86.c | 13 +++++++++++++
qemu/hw/pcspk.c | 43 +++++++++++++++++++++++++++++++++++++++++--
2 files changed, 54 insertions(+), 2 deletions(-)

diff --git a/libkvm/libkvm-x86.c b/libkvm/libkvm-x86.c
index 2fc4fce..03b1939 100644
--- a/libkvm/libkvm-x86.c
+++ b/libkvm/libkvm-x86.c
@@ -59,6 +59,19 @@ int kvm_create_pit(kvm_context_t kvm)

kvm->pit_in_kernel = 0;
if (!kvm->no_pit_creation) {
+#ifdef KVM_CAP_PIT_NOSPKR
+ r = ioctl(kvm->fd, KVM_CHECK_EXTENSION, KVM_CAP_PIT_NOSPKR);
+ if (r > 0) {
+ r = ioctl(kvm->vm_fd, KVM_CREATE_PIT_NOSPKR);
+ if (r >= 0) {
+ kvm->pit_in_kernel = 1;
+ return 0;
+ } else {
+ fprintf(stderr, "Create kernel PIC irqchip failed\n");
+ return r;
+ }
+ }
+#endif
r = ioctl(kvm->fd, KVM_CHECK_EXTENSION, KVM_CAP_PIT);
if (r > 0) {
r = ioctl(kvm->vm_fd, KVM_CREATE_PIT);
diff --git a/qemu/hw/pcspk.c b/qemu/hw/pcspk.c
index ec1d0c6..4752518 100644
--- a/qemu/hw/pcspk.c
+++ b/qemu/hw/pcspk.c
@@ -27,6 +27,8 @@
#include "isa.h"
#include "audio/audio.h"
#include "qemu-timer.h"
+#include "i8254.h"
+#include "qemu-kvm.h"

#define PCSPK_BUF_LEN 1792
#define PCSPK_SAMPLE_RATE 32000
@@ -71,7 +73,15 @@ static void pcspk_callback(void *opaque, int free)
{
PCSpkState *s = opaque;
unsigned int n;
+#ifdef USE_KVM_PIT
+ struct kvm_pit_state pit_state;

+ if (kvm_enabled() && qemu_kvm_pit_in_kernel()) {
+ kvm_get_pit(kvm_context, &pit_state);
+ s->pit->channels[2].mode = pit_state.channels[2].mode;
+ s->pit->channels[2].count = pit_state.channels[2].count;
+ }
+#endif
if (pit_get_mode(s->pit, 2) != 3)
return;

@@ -120,7 +130,17 @@ static uint32_t pcspk_ioport_read(void *opaque, uint32_t addr)
{
PCSpkState *s = opaque;
int out;
-
+#ifdef USE_KVM_PIT
+ struct kvm_pit_state pit_state;
+
+ if (kvm_enabled() && qemu_kvm_pit_in_kernel()) {
+ kvm_get_pit(kvm_context, &pit_state);
+ s->pit->channels[2].mode = pit_state.channels[2].mode;
+ s->pit->channels[2].count = pit_state.channels[2].count;
+ s->pit->channels[2].count_load_time = pit_state.channels[2].count_load_time;
+ s->pit->channels[2].gate = pit_state.channels[2].gate;
+ }
+#endif
s->dummy_refresh_clock ^= (1 << 4);
out = pit_get_out(s->pit, 2, qemu_get_clock(vm_clock)) << 5;

@@ -131,7 +151,17 @@ static void pcspk_ioport_write(void *opaque, uint32_t addr, uint32_t val)
{
PCSpkState *s = opaque;
const int gate = val & 1;
-
+#ifdef USE_KVM_PIT
+ struct kvm_pit_state pit_state;
+
+ if (kvm_enabled() && qemu_kvm_pit_in_kernel()) {
+ kvm_get_pit(kvm_context, &pit_state);
+ s->pit->channels[2].mode = pit_state.channels[2].mode;
+ s->pit->channels[2].count = pit_state.channels[2].count;
+ s->pit->channels[2].count_load_time = pit_state.channels[2].count_load_time;
+ s->pit->channels[2].gate = pit_state.channels[2].gate;
+ }
+#endif
s->data_on = (val >> 1) & 1;
pit_set_gate(s->pit, 2, gate);
if (s->voice) {
@@ -139,6 +169,15 @@ static void pcspk_ioport_write(void *opaque, uint32_t addr, uint32_t val)
s->play_pos = 0;
AUD_set_active_out(s->voice, gate & s->data_on);
}
+#ifdef USE_KVM_PIT
+ if (kvm_enabled() && qemu_kvm_pit_in_kernel()) {
+ pit_state.channels[2].mode = s->pit->channels[2].mode;
+ pit_state.channels[2].count = s->pit->channels[2].count;
+ pit_state.channels[2].count_load_time = s->pit->channels[2].count_load_time;
+ pit_state.channels[2].gate = s->pit->channels[2].gate;
+ kvm_set_pit(kvm_context, &pit_state);
+ }
+#endif
}

void pcspk_init(PITState *pit)

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