In preparation for threaded execution, make the virtio block device code safe by introducing a per-device mutex.
Cc: Asias He <[email protected]> Cc: Cyrill Gorcunov <[email protected]> Cc: Ingo Molnar <[email protected]> Signed-off-by: Pekka Enberg <[email protected]> --- tools/kvm/virtio-blk.c | 41 +++++++++++++++++++++++++++++++++-------- 1 files changed, 33 insertions(+), 8 deletions(-) diff --git a/tools/kvm/virtio-blk.c b/tools/kvm/virtio-blk.c index 874e92e..8f1c684 100644 --- a/tools/kvm/virtio-blk.c +++ b/tools/kvm/virtio-blk.c @@ -11,8 +11,9 @@ #include <linux/virtio_ring.h> #include <linux/virtio_blk.h> + #include <inttypes.h> -#include <assert.h> +#include <pthread.h> #define VIRTIO_BLK_IRQ 14 @@ -21,6 +22,8 @@ #define VIRTIO_BLK_QUEUE_SIZE 128 struct blk_device { + pthread_mutex_t mutex; + struct virtio_blk_config blk_config; uint32_t host_features; uint32_t guest_features; @@ -36,6 +39,8 @@ struct blk_device { #define DISK_SEG_MAX 126 static struct blk_device blk_device = { + .mutex = PTHREAD_MUTEX_INITIALIZER, + .blk_config = (struct virtio_blk_config) { /* VIRTIO_BLK_F_SEG_MAX */ .seg_max = DISK_SEG_MAX, @@ -63,6 +68,10 @@ static bool virtio_blk_pci_io_device_specific_in(void *data, unsigned long offse static bool virtio_blk_pci_io_in(struct kvm *self, uint16_t port, void *data, int size, uint32_t count) { unsigned long offset; + bool ret = true; + + if (pthread_mutex_lock(&blk_device.mutex) < 0) + die("pthread_mutex_lock"); offset = port - IOPORT_VIRTIO_BLK; @@ -71,7 +80,8 @@ static bool virtio_blk_pci_io_in(struct kvm *self, uint16_t port, void *data, in ioport__write32(data, blk_device.host_features); break; case VIRTIO_PCI_GUEST_FEATURES: - return false; + ret = false; + goto out_unlock; case VIRTIO_PCI_QUEUE_PFN: ioport__write32(data, blk_device.vqs[blk_device.queue_selector].pfn); break; @@ -80,7 +90,8 @@ static bool virtio_blk_pci_io_in(struct kvm *self, uint16_t port, void *data, in break; case VIRTIO_PCI_QUEUE_SEL: case VIRTIO_PCI_QUEUE_NOTIFY: - return false; + ret = false; + goto out_unlock; case VIRTIO_PCI_STATUS: ioport__write8(data, blk_device.status); break; @@ -92,15 +103,19 @@ static bool virtio_blk_pci_io_in(struct kvm *self, uint16_t port, void *data, in ioport__write16(data, blk_device.config_vector); break; default: - return virtio_blk_pci_io_device_specific_in(data, offset, size, count); + ret = virtio_blk_pci_io_device_specific_in(data, offset, size, count); + goto out_unlock; }; - return true; +out_unlock: + if (pthread_mutex_unlock(&blk_device.mutex) < 0) + die("pthread_mutex_unlock"); + + return ret; } static bool virtio_blk_do_io_request(struct kvm *self, struct virt_queue *queue) { - struct iovec iov[VIRTIO_BLK_QUEUE_SIZE]; struct virtio_blk_outhdr *req; uint32_t block_len, block_cnt; @@ -159,9 +174,14 @@ static void virtio_blk_handle_callback(struct kvm *self, uint16_t queue_index) kvm__irq_line(self, VIRTIO_BLK_IRQ, 1); } + static bool virtio_blk_pci_io_out(struct kvm *self, uint16_t port, void *data, int size, uint32_t count) { unsigned long offset; + bool ret = true; + + if (pthread_mutex_lock(&blk_device.mutex) < 0) + die("pthread_mutex_lock"); offset = port - IOPORT_VIRTIO_BLK; @@ -201,10 +221,15 @@ static bool virtio_blk_pci_io_out(struct kvm *self, uint16_t port, void *data, i case VIRTIO_MSI_QUEUE_VECTOR: break; default: - return false; + ret = false; + goto out_unlock; }; - return true; +out_unlock: + if (pthread_mutex_unlock(&blk_device.mutex) < 0) + die("pthread_mutex_unlock"); + + return ret; } static struct ioport_operations virtio_blk_io_ops = { -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
