| Message ID | 1457324608-11434-4-git-send-email-peterx@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Mar 07, 2016 at 12:23:28PM +0800, Peter Xu wrote: > For emulated GIC capabilities, currently only gicv2 is supported. We > need to add gicv3 in when emulated gicv3 ready. For KVM accelerated ARM > VM, we detect the capability bits using ioctls. > > When probing the KVM capabilities, we cannot leverage existing helper > functions like kvm_create_device() since QEMU might be using TCG while > probing (actually this is the case for libvirt probing). So, one > temporary VM is created to do the probing. > > Signed-off-by: Peter Xu <peterx@redhat.com> > --- > target-arm/machine.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 104 insertions(+), 1 deletion(-) > > diff --git a/target-arm/machine.c b/target-arm/machine.c > index 60bd5c1..ff50411 100644 > --- a/target-arm/machine.c > +++ b/target-arm/machine.c > @@ -1,3 +1,5 @@ > +#include <linux/kvm.h> > +#include <sys/ioctl.h> > #include "qemu/osdep.h" > #include "hw/hw.h" > #include "hw/boards.h" > @@ -347,7 +349,108 @@ const char *gicv3_class_name(void) > exit(1); > } > > +static GICCapability *gic_cap_new(int version) > +{ > + GICCapability *cap = g_new0(GICCapability, 1); > + cap->version = version; > + /* by default, support none */ > + cap->emulated = false; > + cap->kernel = false; > + return cap; > +} > + > +static GICCapabilityList *gic_cap_list_add(GICCapabilityList *head, > + GICCapability *cap) > +{ > + GICCapabilityList *item = g_new0(GICCapabilityList, 1); > + item->value = cap; > + item->next = head; > + return item; > +} > + > +#ifdef CONFIG_KVM > +/* > + * This is merely the same as kvm_create_device(). The only > + * difference is we are using raw fds rather than KVMState, so that > + * we can use it even without kvm_state initialized. > + */ > +static int kvm_create_device_fds(int kvm_fd, int vmfd, > + uint64_t type, bool test) I don't think we need this helper function. Who else will call it? Particularly without test==true? Anyway, I think three ioctls directly called from qmp_query_gic_capability should be OK. > +{ > + int ret; > + struct kvm_create_device create_dev; > + > + create_dev.type = type; > + create_dev.fd = -1; > + create_dev.flags = test ? KVM_CREATE_DEVICE_TEST : 0; > + > + if (ioctl(kvm_fd, KVM_CHECK_EXTENSION, KVM_CAP_DEVICE_CTRL) <= 0) { > + return -ENOTSUP; > + } > + > + ret = ioctl(vmfd, KVM_CREATE_DEVICE, &create_dev); > + if (ret) { > + return ret; > + } > + > + return test ? 0 : create_dev.fd; > +} > +#endif > + > GICCapabilityList *qmp_query_gic_capability(Error **errp) > { > - return NULL; > + GICCapabilityList *head = NULL; > + GICCapability *v2 = gic_cap_new(2), *v3 = gic_cap_new(3); > + > + v2->emulated = true; > + /* FIXME: we'd change to true after we get emulated GICv3. */ > + v3->emulated = false; > + > +#ifdef CONFIG_KVM > + { > + /* > + * HACK: here we create one temporary VM, do the probing, > + * then release it properly. > + */ > + int kvm_fd = -1; > + int vmfd = -1; > + > + kvm_fd = qemu_open("/dev/kvm", O_RDWR); > + if (kvm_fd == -1) { > + /* KVM may not enabled on host, which is fine. */ > + goto out; > + } > + > + do { > + /* For ARM, VM type could only be zero now. */ > + vmfd = ioctl(kvm_fd, KVM_CREATE_VM, 0); > + } while (vmfd == -EINTR); > + > + if (vmfd < 0) { > + goto kvm_fd_close; > + } > + > + /* Test KVM GICv2 */ > + if (kvm_create_device_fds(kvm_fd, vmfd, KVM_DEV_TYPE_ARM_VGIC_V2, > + true) >= 0) { > + v2->kernel = true; > + } > + > + /* Test KVM GICv3 */ > + if (kvm_create_device_fds(kvm_fd, vmfd, KVM_DEV_TYPE_ARM_VGIC_V3, > + true) >= 0) { > + v3->kernel = true; > + } > + > + close(vmfd); > +kvm_fd_close: > + close(kvm_fd); > + } > +#endif > + > +out: > + head = gic_cap_list_add(head, v2); > + head = gic_cap_list_add(head, v3); > + > + return head; > } > -- > 2.4.3 > >
On Mon, Mar 07, 2016 at 06:12:38AM +0100, Andrew Jones wrote: > On Mon, Mar 07, 2016 at 12:23:28PM +0800, Peter Xu wrote: > > +#ifdef CONFIG_KVM > > +/* > > + * This is merely the same as kvm_create_device(). The only > > + * difference is we are using raw fds rather than KVMState, so that > > + * we can use it even without kvm_state initialized. > > + */ > > +static int kvm_create_device_fds(int kvm_fd, int vmfd, > > + uint64_t type, bool test) > > I don't think we need this helper function. Who else will call it? > Particularly without test==true? Anyway, I think three ioctls directly > called from qmp_query_gic_capability should be OK. Right. However, I would still consider using a helper function if you would not mind. E.g, how about this: #ifdef CONFIG_KVM /* Test whether KVM support specific device. */ static inline int kvm_support_device(int vmfd, uint64_t type) { struct kvm_create_device create_dev = { .type = type, .fd = -1, .flags = KVM_CREATE_DEVICE_TEST, }; return ioctl(vmfd, KVM_CREATE_DEVICE, &create_dev); } #endif Thanks. Peter
On Mon, Mar 07, 2016 at 01:38:24PM +0800, Peter Xu wrote: > On Mon, Mar 07, 2016 at 06:12:38AM +0100, Andrew Jones wrote: > > On Mon, Mar 07, 2016 at 12:23:28PM +0800, Peter Xu wrote: > > > +#ifdef CONFIG_KVM > > > +/* > > > + * This is merely the same as kvm_create_device(). The only > > > + * difference is we are using raw fds rather than KVMState, so that > > > + * we can use it even without kvm_state initialized. > > > + */ > > > +static int kvm_create_device_fds(int kvm_fd, int vmfd, > > > + uint64_t type, bool test) > > > > I don't think we need this helper function. Who else will call it? > > Particularly without test==true? Anyway, I think three ioctls directly > > called from qmp_query_gic_capability should be OK. > > Right. However, I would still consider using a helper function if > you would not mind. E.g, how about this: Fine by me. Thanks, drew > > #ifdef CONFIG_KVM > /* Test whether KVM support specific device. */ > static inline int kvm_support_device(int vmfd, uint64_t type) > { > struct kvm_create_device create_dev = { > .type = type, > .fd = -1, > .flags = KVM_CREATE_DEVICE_TEST, > }; > return ioctl(vmfd, KVM_CREATE_DEVICE, &create_dev); > } > #endif > > Thanks. > Peter >
diff --git a/target-arm/machine.c b/target-arm/machine.c index 60bd5c1..ff50411 100644 --- a/target-arm/machine.c +++ b/target-arm/machine.c @@ -1,3 +1,5 @@ +#include <linux/kvm.h> +#include <sys/ioctl.h> #include "qemu/osdep.h" #include "hw/hw.h" #include "hw/boards.h" @@ -347,7 +349,108 @@ const char *gicv3_class_name(void) exit(1); } +static GICCapability *gic_cap_new(int version) +{ + GICCapability *cap = g_new0(GICCapability, 1); + cap->version = version; + /* by default, support none */ + cap->emulated = false; + cap->kernel = false; + return cap; +} + +static GICCapabilityList *gic_cap_list_add(GICCapabilityList *head, + GICCapability *cap) +{ + GICCapabilityList *item = g_new0(GICCapabilityList, 1); + item->value = cap; + item->next = head; + return item; +} + +#ifdef CONFIG_KVM +/* + * This is merely the same as kvm_create_device(). The only + * difference is we are using raw fds rather than KVMState, so that + * we can use it even without kvm_state initialized. + */ +static int kvm_create_device_fds(int kvm_fd, int vmfd, + uint64_t type, bool test) +{ + int ret; + struct kvm_create_device create_dev; + + create_dev.type = type; + create_dev.fd = -1; + create_dev.flags = test ? KVM_CREATE_DEVICE_TEST : 0; + + if (ioctl(kvm_fd, KVM_CHECK_EXTENSION, KVM_CAP_DEVICE_CTRL) <= 0) { + return -ENOTSUP; + } + + ret = ioctl(vmfd, KVM_CREATE_DEVICE, &create_dev); + if (ret) { + return ret; + } + + return test ? 0 : create_dev.fd; +} +#endif + GICCapabilityList *qmp_query_gic_capability(Error **errp) { - return NULL; + GICCapabilityList *head = NULL; + GICCapability *v2 = gic_cap_new(2), *v3 = gic_cap_new(3); + + v2->emulated = true; + /* FIXME: we'd change to true after we get emulated GICv3. */ + v3->emulated = false; + +#ifdef CONFIG_KVM + { + /* + * HACK: here we create one temporary VM, do the probing, + * then release it properly. + */ + int kvm_fd = -1; + int vmfd = -1; + + kvm_fd = qemu_open("/dev/kvm", O_RDWR); + if (kvm_fd == -1) { + /* KVM may not enabled on host, which is fine. */ + goto out; + } + + do { + /* For ARM, VM type could only be zero now. */ + vmfd = ioctl(kvm_fd, KVM_CREATE_VM, 0); + } while (vmfd == -EINTR); + + if (vmfd < 0) { + goto kvm_fd_close; + } + + /* Test KVM GICv2 */ + if (kvm_create_device_fds(kvm_fd, vmfd, KVM_DEV_TYPE_ARM_VGIC_V2, + true) >= 0) { + v2->kernel = true; + } + + /* Test KVM GICv3 */ + if (kvm_create_device_fds(kvm_fd, vmfd, KVM_DEV_TYPE_ARM_VGIC_V3, + true) >= 0) { + v3->kernel = true; + } + + close(vmfd); +kvm_fd_close: + close(kvm_fd); + } +#endif + +out: + head = gic_cap_list_add(head, v2); + head = gic_cap_list_add(head, v3); + + return head; }
For emulated GIC capabilities, currently only gicv2 is supported. We need to add gicv3 in when emulated gicv3 ready. For KVM accelerated ARM VM, we detect the capability bits using ioctls. When probing the KVM capabilities, we cannot leverage existing helper functions like kvm_create_device() since QEMU might be using TCG while probing (actually this is the case for libvirt probing). So, one temporary VM is created to do the probing. Signed-off-by: Peter Xu <peterx@redhat.com> --- target-arm/machine.c | 105 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 104 insertions(+), 1 deletion(-)