On 4/2/10, Paolo Bonzini <pbonz...@redhat.com> wrote:
> This allows limited use of kvm functions (which will return ENOSYS)
> even in once-compiled modules. The patch also improves a bit the error
> messages for KVM initialization.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> What about this instead? I don't like that kvm-stub.c is
> compiled per-target too, but it's basically impossible to
> change this without major changes to the build system.
>
> Makefile.target | 2 +
> kvm-all.c | 6 ++-
> kvm-stub.c | 135
> +++++++++++++++++++++++++++++++++++++++++++++++++++++++
> kvm.h | 13 +----
> vl.c | 16 +++----
> 5 files changed, 151 insertions(+), 21 deletions(-)
> create mode 100644 kvm-stub.c
>
> diff --git a/Makefile.target b/Makefile.target
> index 167fc8d..c504617 100644
> --- a/Makefile.target
> +++ b/Makefile.target
> @@ -1,6 +1,7 @@
> # -*- Mode: makefile -*-
>
> GENERATED_HEADERS = config-target.h
> +CONFIG_NO_KVM = $(if $(subst n,,$(CONFIG_KVM)),n,y)
>
> include ../config-host.mak
> include config-devices.mak
> @@ -170,6 +171,7 @@ obj-y += vhost_net.o
> obj-$(CONFIG_VHOST_NET) += vhost.o
> obj-y += rwhandler.o
> obj-$(CONFIG_KVM) += kvm.o kvm-all.o
> +obj-$(CONFIG_NO_KVM) += kvm-stub.o
> LIBS+=-lz
>
> QEMU_CFLAGS += $(VNC_TLS_CFLAGS)
> diff --git a/kvm-all.c b/kvm-all.c
> index 7aa5e57..373fd34 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -1157,9 +1157,9 @@ int kvm_set_signal_mask(CPUState *env, const sigset_t
> *sigset)
> return r;
> }
>
> -#ifdef KVM_IOEVENTFD
> int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr, uint16_t val, bool
> assign)
> {
> +#ifdef KVM_IOEVENTFD
> struct kvm_ioeventfd kick = {
> .datamatch = val,
> .addr = addr,
> @@ -1176,5 +1176,7 @@ int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr,
> uint16_t val, bool assign)
> if (r < 0)
> return r;
> return 0;
> -}
> +#else
> + return -ENOSYS;
> #endif
> +}
> diff --git a/kvm-stub.c b/kvm-stub.c
> new file mode 100644
> index 0000000..80bb908
> --- /dev/null
> +++ b/kvm-stub.c
> @@ -0,0 +1,135 @@
> +/*
> + * QEMU KVM stub
> + *
> + * Copyright Red Hat, Inc. 2010
> + *
> + * Author: Paolo Bonzini <pbonz...@redhat.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 "qemu-common.h"
> +#include "sysemu.h"
> +#include "hw/hw.h"
> +#include "gdbstub.h"
> +#include "kvm.h"
> +
> +int kvm_irqchip_in_kernel(void)
> +{
> + return 0;
> +}
> +
> +int kvm_pit_in_kernel(void)
> +{
> + return 0;
> +}
> +
> +
> +int kvm_init_vcpu(CPUState *env)
> +{
> + return -ENOSYS;
> +}
> +
> +int kvm_log_start(target_phys_addr_t phys_addr, ram_addr_t size)
> +{
> + return -ENOSYS;
> +}
> +
> +int kvm_log_stop(target_phys_addr_t phys_addr, ram_addr_t size)
> +{
> + return -ENOSYS;
> +}
> +
> +int kvm_coalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
> +{
> + return -ENOSYS;
> +}
> +
> +int kvm_uncoalesce_mmio_region(target_phys_addr_t start, ram_addr_t size)
> +{
> + return -ENOSYS;
> +}
> +
> +int kvm_check_extension(KVMState *s, unsigned int extension)
> +{
> + return 0;
> +}
> +
> +int kvm_init(int smp_cpus)
> +{
> + return -ENOSYS;
> +}
> +
> +void kvm_flush_coalesced_mmio_buffer(void)
> +{
> +}
> +
> +void kvm_cpu_synchronize_state(CPUState *env)
> +{
> +}
> +
> +void kvm_cpu_synchronize_post_reset(CPUState *env)
> +{
> +}
> +
> +void kvm_cpu_synchronize_post_init(CPUState *env)
> +{
> +}
> +
> +int kvm_cpu_exec(CPUState *env)
> +{
> + abort ();
> +}
> +
> +int kvm_has_sync_mmu(void)
> +{
> + return 0;
> +}
> +
> +int kvm_has_vcpu_events(void)
> +{
> + return 0;
> +}
> +
> +int kvm_has_robust_singlestep(void)
> +{
> + return 0;
> +}
> +
> +void kvm_setup_guest_memory(void *start, size_t size)
> +{
> +}
> +
> +int kvm_update_guest_debug(CPUState *env, unsigned long reinject_trap)
> +{
> + tb_flush(env);
> + return 0;
> +}
> +
> +int kvm_insert_breakpoint(CPUState *current_env, target_ulong addr,
> + target_ulong len, int type)
> +{
> + return -EINVAL;
> +}
> +
> +int kvm_remove_breakpoint(CPUState *current_env, target_ulong addr,
> + target_ulong len, int type)
> +{
> + return -EINVAL;
> +}
> +
> +void kvm_remove_all_breakpoints(CPUState *current_env)
> +{
> +}
> +
> +int kvm_set_signal_mask(CPUState *env, const sigset_t *sigset)
> +{
> + abort();
> +}
> +
> +int kvm_set_ioeventfd_pio_word(int fd, uint16_t addr, uint16_t val, bool
> assign)
> +{
> + return -ENOSYS;
> +}
> diff --git a/kvm.h b/kvm.h
> index 1e5be27..ea3c97d 100644
> --- a/kvm.h
> +++ b/kvm.h
> @@ -23,8 +23,9 @@
> #include <linux/kvm.h>
> #endif
>
> -#ifdef CONFIG_KVM
> extern int kvm_allowed;
> +
> +#if defined CONFIG_KVM || !defined NEED_CPU_H
> #define kvm_enabled() (kvm_allowed)
> #else
> #define kvm_enabled() (0)
> @@ -167,15 +168,7 @@ static inline void cpu_synchronize_post_init(CPUState
> *env)
> }
> }
>
> -#if defined(KVM_IOEVENTFD) && defined(CONFIG_KVM)
> -int kvm_set_ioeventfd_pio_word(int fd, uint16_t adr, uint16_t val, bool
> assign);
> -#else
> -static inline
> -int kvm_set_ioeventfd_pio_word(int fd, uint16_t adr, uint16_t val, bool
> assign)
> -{
> - return -ENOSYS;
> -}
> #endif
>
> -#endif
> +int kvm_set_ioeventfd_pio_word(int fd, uint16_t adr, uint16_t val, bool
> assign);
> #endif
> diff --git a/vl.c b/vl.c
> index 6768cf1..9fe4682 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -3235,10 +3235,6 @@ int main(int argc, char **argv, char **envp)
> do_smbios_option(optarg);
> break;
> case QEMU_OPTION_enable_kvm:
> - if (!(kvm_available())) {
> - printf("Option %s not supported for this target\n",
> popt->name);
> - exit(1);
> - }
> kvm_allowed = 1;
> break;
> case QEMU_OPTION_usb:
> @@ -3585,12 +3581,14 @@ int main(int argc, char **argv, char **envp)
> exit(1);
> }
>
> - if (kvm_enabled()) {
> - int ret;
> -
> - ret = kvm_init(smp_cpus);
> + if (kvm_allowed) {
> + int ret = kvm_init(smp_cpus);
> if (ret < 0) {
> - fprintf(stderr, "failed to initialize KVM\n");
> + if (!kvm_available()) {
> + printf("KVM not supported for this target\n");
> + } else {
> + fprintf(stderr, "failed to initialize KVM: %s\n",
> strerror(-ret));
> + }
Could you stub also kvm_init? Then this part would be simpler because
you can call unconditionally kvm_init. I guess there would be no need
to export kvm_allowed for !CONFIG_KVM case.
