I mixed up files, this patch misses:
/* See if the guest is running */
if (!kvm_cpus[i] || kvm_cpus[i]->thread == 0)
return;
In the beginning of kvm__pause() and kvm__continue(). I'll send an
updated patch.
On Sun, 2011-05-29 at 20:32 +0300, Sasha Levin wrote:
> Allow pausing and unpausing guests running on the host.
> Pausing a guest means that none of the VCPU threads are running
> KVM_RUN until they are unpaused.
>
> Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
> ---
> tools/kvm/include/kvm/kvm-cpu.h | 1 +
> tools/kvm/include/kvm/kvm.h | 4 +++
> tools/kvm/kvm-cpu.c | 18 +++++++++++----
> tools/kvm/kvm-run.c | 4 +-
> tools/kvm/kvm.c | 45 +++++++++++++++++++++++++++++++++++++++
> 5 files changed, 65 insertions(+), 7 deletions(-)
>
> diff --git a/tools/kvm/include/kvm/kvm-cpu.h b/tools/kvm/include/kvm/kvm-cpu.h
> index b2b6fce..4d99246 100644
> --- a/tools/kvm/include/kvm/kvm-cpu.h
> +++ b/tools/kvm/include/kvm/kvm-cpu.h
> @@ -23,6 +23,7 @@ struct kvm_cpu {
> struct kvm_msrs *msrs; /* dynamically allocated */
>
> u8 is_running;
> + u8 paused;
> };
>
> struct kvm_cpu *kvm_cpu__init(struct kvm *kvm, unsigned long cpu_id);
> diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
> index 6a17362..d22a849 100644
> --- a/tools/kvm/include/kvm/kvm.h
> +++ b/tools/kvm/include/kvm/kvm.h
> @@ -12,6 +12,7 @@
> #define KVM_32BIT_GAP_START ((1ULL << 32) - KVM_32BIT_GAP_SIZE)
>
> #define SIGKVMEXIT (SIGRTMIN + 0)
> +#define SIGKVMPAUSE (SIGRTMIN + 1)
>
> struct kvm {
> int sys_fd; /* For system ioctls(), i.e. /dev/kvm */
> @@ -50,6 +51,9 @@ bool kvm__emulate_io(struct kvm *kvm, u16 port, void *data, int direction, int s
> bool kvm__emulate_mmio(struct kvm *kvm, u64 phys_addr, u8 *data, u32 len, u8 is_write);
> bool kvm__register_mmio(u64 phys_addr, u64 phys_addr_len, void (*kvm_mmio_callback_fn)(u64 addr, u8 *data, u32 len, u8 is_write));
> bool kvm__deregister_mmio(u64 phys_addr);
> +void kvm__pause(void);
> +void kvm__continue(void);
> +void kvm__notify_paused(void);
>
> /*
> * Debugging
> diff --git a/tools/kvm/kvm-cpu.c b/tools/kvm/kvm-cpu.c
> index de0591f..81f479f 100644
> --- a/tools/kvm/kvm-cpu.c
> +++ b/tools/kvm/kvm-cpu.c
> @@ -383,11 +383,15 @@ void kvm_cpu__run(struct kvm_cpu *vcpu)
> die_perror("KVM_RUN failed");
> }
>
> -static void kvm_cpu_exit_handler(int signum)
> +static void kvm_cpu_signal_handler(int signum)
> {
> - if (current_kvm_cpu->is_running) {
> - current_kvm_cpu->is_running = false;
> - pthread_kill(pthread_self(), SIGKVMEXIT);
> + if (signum == SIGKVMEXIT) {
> + if (current_kvm_cpu->is_running) {
> + current_kvm_cpu->is_running = false;
> + pthread_kill(pthread_self(), SIGKVMEXIT);
> + }
> + } else if (signum == SIGKVMPAUSE) {
> + current_kvm_cpu->paused = 1;
> }
> }
>
> @@ -400,12 +404,16 @@ int kvm_cpu__start(struct kvm_cpu *cpu)
>
> pthread_sigmask(SIG_BLOCK, &sigset, NULL);
>
> - signal(SIGKVMEXIT, kvm_cpu_exit_handler);
> + signal(SIGKVMEXIT, kvm_cpu_signal_handler);
> + signal(SIGKVMPAUSE, kvm_cpu_signal_handler);
>
> kvm_cpu__setup_cpuid(cpu);
> kvm_cpu__reset_vcpu(cpu);
>
> for (;;) {
> + if (cpu->paused)
> + kvm__notify_paused();
> +
> kvm_cpu__run(cpu);
>
> switch (cpu->kvm_run->exit_reason) {
> diff --git a/tools/kvm/kvm-run.c b/tools/kvm/kvm-run.c
> index 48b8e70..761ac0d 100644
> --- a/tools/kvm/kvm-run.c
> +++ b/tools/kvm/kvm-run.c
> @@ -47,8 +47,8 @@
> #define MIN_RAM_SIZE_MB (64ULL)
> #define MIN_RAM_SIZE_BYTE (MIN_RAM_SIZE_MB << MB_SHIFT)
>
> -static struct kvm *kvm;
> -static struct kvm_cpu *kvm_cpus[KVM_NR_CPUS];
> +struct kvm *kvm;
> +struct kvm_cpu *kvm_cpus[KVM_NR_CPUS];
> __thread struct kvm_cpu *current_kvm_cpu;
>
> static u64 ram_size;
> diff --git a/tools/kvm/kvm.c b/tools/kvm/kvm.c
> index 1d756e0..1e22566 100644
> --- a/tools/kvm/kvm.c
> +++ b/tools/kvm/kvm.c
> @@ -6,6 +6,8 @@
> #include "kvm/interrupt.h"
> #include "kvm/mptable.h"
> #include "kvm/util.h"
> +#include "kvm/mutex.h"
> +#include "kvm/kvm-cpu.h"
>
> #include <linux/kvm.h>
>
> @@ -25,6 +27,7 @@
> #include <stdio.h>
> #include <fcntl.h>
> #include <time.h>
> +#include <sys/eventfd.h>
>
> #define DEFINE_KVM_EXIT_REASON(reason) [reason] = #reason
>
> @@ -68,6 +71,10 @@ struct {
> { DEFINE_KVM_EXT(KVM_CAP_EXT_CPUID) },
> };
>
> +extern struct kvm_cpu *kvm_cpus[KVM_NR_CPUS];
> +static int pause_event;
> +static DEFINE_MUTEX(pause_lock);
> +
> static bool kvm__supports_extension(struct kvm *kvm, unsigned int extension)
> {
> int ret;
> @@ -575,3 +582,41 @@ void kvm__dump_mem(struct kvm *kvm, unsigned long addr, unsigned long size)
> p[n + 4], p[n + 5], p[n + 6], p[n + 7]);
> }
> }
> +
> +void kvm__pause(void)
> +{
> + int i, paused_vcpus = 0;
> +
> + mutex_lock(&pause_lock);
> +
> + pause_event = eventfd(0, 0);
> + if (pause_event < 0)
> + die("Failed creating pause notification event");
> + for (i = 0; i < kvm.nrcpus; i++)
> + pthread_kill(kvm_cpus[i]->thread, SIGKVMPAUSE);
> +
> + while (paused_vcpus < kvm.nrcpus) {
> + u64 cur_read;
> +
> + if (read(pause_event, &cur_read, sizeof(cur_read)) < 0)
> + die("Failed reading pause event");
> + paused_vcpus += cur_read;
> + }
> + close(pause_event);
> +}
> +
> +void kvm__continue(void)
> +{
> + mutex_unlock(&pause_lock);
> +}
> +
> +void kvm__notify_paused(void)
> +{
> + u64 p = 1;
> +
> + if (write(pause_event, &p, sizeof(p)) < 0)
> + die("Failed notifying of paused VCPU.");
> +
> + mutex_lock(&pause_lock);
> + mutex_unlock(&pause_lock);
> +}
--
Sasha.
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