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authorLinus Torvalds <torvalds@linux-foundation.org>2018-11-01 14:42:49 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-11-01 14:42:49 -0700
commitb5b1de3537e2cd8f52971224a1be24bb3ce34a65 (patch)
treecd199730744628103c36b14c878b94af4fea4735
parent90de1fb83e7c760aa403381f072486fc4e3e8b5f (diff)
parent79f800b2e76923cd8ce0aa659cb5c019d9643bc9 (diff)
downloadlinux-b5b1de3537e2cd8f52971224a1be24bb3ce34a65.tar.gz
Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio/vhost updates from Michael Tsirkin: "Fixes and tweaks: - virtio balloon page hinting support - vhost scsi control queue - misc fixes" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: MAINTAINERS: remove reference to bogus vsock file vhost/scsi: Use common handling code in request queue handler vhost/scsi: Extract common handling code from control queue handler vhost/scsi: Respond to control queue operations vhost/scsi: truncate T10 PI iov_iter to prot_bytes virtio-balloon: VIRTIO_BALLOON_F_PAGE_POISON mm/page_poison: expose page_poisoning_enabled to kernel modules virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT kvm_config: add CONFIG_VIRTIO_MENU
-rw-r--r--MAINTAINERS1
-rw-r--r--drivers/vhost/scsi.c426
-rw-r--r--drivers/virtio/virtio_balloon.c374
-rw-r--r--include/uapi/linux/virtio_balloon.h8
-rw-r--r--kernel/configs/kvm_guest.config1
-rw-r--r--mm/page_poison.c6
6 files changed, 685 insertions, 131 deletions
diff --git a/MAINTAINERS b/MAINTAINERS
index 690c2f68a401..bb97067d0568 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15858,7 +15858,6 @@ F: net/vmw_vsock/virtio_transport_common.c
F: net/vmw_vsock/virtio_transport.c
F: drivers/net/vsockmon.c
F: drivers/vhost/vsock.c
-F: drivers/vhost/vsock.h
F: tools/testing/vsock/
VIRTIO CONSOLE DRIVER
diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index c24bb690680b..50dffe83714c 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -203,6 +203,19 @@ struct vhost_scsi {
int vs_events_nr; /* num of pending events, protected by vq->mutex */
};
+/*
+ * Context for processing request and control queue operations.
+ */
+struct vhost_scsi_ctx {
+ int head;
+ unsigned int out, in;
+ size_t req_size, rsp_size;
+ size_t out_size, in_size;
+ u8 *target, *lunp;
+ void *req;
+ struct iov_iter out_iter;
+};
+
static struct workqueue_struct *vhost_scsi_workqueue;
/* Global spinlock to protect vhost_scsi TPG list for vhost IOCTL access */
@@ -800,24 +813,120 @@ vhost_scsi_send_bad_target(struct vhost_scsi *vs,
pr_err("Faulted on virtio_scsi_cmd_resp\n");
}
+static int
+vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
+ struct vhost_scsi_ctx *vc)
+{
+ int ret = -ENXIO;
+
+ vc->head = vhost_get_vq_desc(vq, vq->iov,
+ ARRAY_SIZE(vq->iov), &vc->out, &vc->in,
+ NULL, NULL);
+
+ pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
+ vc->head, vc->out, vc->in);
+
+ /* On error, stop handling until the next kick. */
+ if (unlikely(vc->head < 0))
+ goto done;
+
+ /* Nothing new? Wait for eventfd to tell us they refilled. */
+ if (vc->head == vq->num) {
+ if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
+ vhost_disable_notify(&vs->dev, vq);
+ ret = -EAGAIN;
+ }
+ goto done;
+ }
+
+ /*
+ * Get the size of request and response buffers.
+ * FIXME: Not correct for BIDI operation
+ */
+ vc->out_size = iov_length(vq->iov, vc->out);
+ vc->in_size = iov_length(&vq->iov[vc->out], vc->in);
+
+ /*
+ * Copy over the virtio-scsi request header, which for a
+ * ANY_LAYOUT enabled guest may span multiple iovecs, or a
+ * single iovec may contain both the header + outgoing
+ * WRITE payloads.
+ *
+ * copy_from_iter() will advance out_iter, so that it will
+ * point at the start of the outgoing WRITE payload, if
+ * DMA_TO_DEVICE is set.
+ */
+ iov_iter_init(&vc->out_iter, WRITE, vq->iov, vc->out, vc->out_size);
+ ret = 0;
+
+done:
+ return ret;
+}
+
+static int
+vhost_scsi_chk_size(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc)
+{
+ if (unlikely(vc->in_size < vc->rsp_size)) {
+ vq_err(vq,
+ "Response buf too small, need min %zu bytes got %zu",
+ vc->rsp_size, vc->in_size);
+ return -EINVAL;
+ } else if (unlikely(vc->out_size < vc->req_size)) {
+ vq_err(vq,
+ "Request buf too small, need min %zu bytes got %zu",
+ vc->req_size, vc->out_size);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int
+vhost_scsi_get_req(struct vhost_virtqueue *vq, struct vhost_scsi_ctx *vc,
+ struct vhost_scsi_tpg **tpgp)
+{
+ int ret = -EIO;
+
+ if (unlikely(!copy_from_iter_full(vc->req, vc->req_size,
+ &vc->out_iter))) {
+ vq_err(vq, "Faulted on copy_from_iter\n");
+ } else if (unlikely(*vc->lunp != 1)) {
+ /* virtio-scsi spec requires byte 0 of the lun to be 1 */
+ vq_err(vq, "Illegal virtio-scsi lun: %u\n", *vc->lunp);
+ } else {
+ struct vhost_scsi_tpg **vs_tpg, *tpg;
+
+ vs_tpg = vq->private_data; /* validated at handler entry */
+
+ tpg = READ_ONCE(vs_tpg[*vc->target]);
+ if (unlikely(!tpg)) {
+ vq_err(vq, "Target 0x%x does not exist\n", *vc->target);
+ } else {
+ if (tpgp)
+ *tpgp = tpg;
+ ret = 0;
+ }
+ }
+
+ return ret;
+}
+
static void
vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
{
struct vhost_scsi_tpg **vs_tpg, *tpg;
struct virtio_scsi_cmd_req v_req;
struct virtio_scsi_cmd_req_pi v_req_pi;
+ struct vhost_scsi_ctx vc;
struct vhost_scsi_cmd *cmd;
- struct iov_iter out_iter, in_iter, prot_iter, data_iter;
+ struct iov_iter in_iter, prot_iter, data_iter;
u64 tag;
u32 exp_data_len, data_direction;
- unsigned int out = 0, in = 0;
- int head, ret, prot_bytes;
- size_t req_size, rsp_size = sizeof(struct virtio_scsi_cmd_resp);
- size_t out_size, in_size;
+ int ret, prot_bytes;
u16 lun;
- u8 *target, *lunp, task_attr;
+ u8 task_attr;
bool t10_pi = vhost_has_feature(vq, VIRTIO_SCSI_F_T10_PI);
- void *req, *cdb;
+ void *cdb;
mutex_lock(&vq->mutex);
/*
@@ -828,85 +937,47 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
if (!vs_tpg)
goto out;
+ memset(&vc, 0, sizeof(vc));
+ vc.rsp_size = sizeof(struct virtio_scsi_cmd_resp);
+
vhost_disable_notify(&vs->dev, vq);
for (;;) {
- head = vhost_get_vq_desc(vq, vq->iov,
- ARRAY_SIZE(vq->iov), &out, &in,
- NULL, NULL);
- pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
- head, out, in);
- /* On error, stop handling until the next kick. */
- if (unlikely(head < 0))
- break;
- /* Nothing new? Wait for eventfd to tell us they refilled. */
- if (head == vq->num) {
- if (unlikely(vhost_enable_notify(&vs->dev, vq))) {
- vhost_disable_notify(&vs->dev, vq);
- continue;
- }
- break;
- }
- /*
- * Check for a sane response buffer so we can report early
- * errors back to the guest.
- */
- if (unlikely(vq->iov[out].iov_len < rsp_size)) {
- vq_err(vq, "Expecting at least virtio_scsi_cmd_resp"
- " size, got %zu bytes\n", vq->iov[out].iov_len);
- break;
- }
+ ret = vhost_scsi_get_desc(vs, vq, &vc);
+ if (ret)
+ goto err;
+
/*
* Setup pointers and values based upon different virtio-scsi
* request header if T10_PI is enabled in KVM guest.
*/
if (t10_pi) {
- req = &v_req_pi;
- req_size = sizeof(v_req_pi);
- lunp = &v_req_pi.lun[0];
- target = &v_req_pi.lun[1];
+ vc.req = &v_req_pi;
+ vc.req_size = sizeof(v_req_pi);
+ vc.lunp = &v_req_pi.lun[0];
+ vc.target = &v_req_pi.lun[1];
} else {
- req = &v_req;
- req_size = sizeof(v_req);
- lunp = &v_req.lun[0];
- target = &v_req.lun[1];
+ vc.req = &v_req;
+ vc.req_size = sizeof(v_req);
+ vc.lunp = &v_req.lun[0];
+ vc.target = &v_req.lun[1];
}
- /*
- * FIXME: Not correct for BIDI operation
- */
- out_size = iov_length(vq->iov, out);
- in_size = iov_length(&vq->iov[out], in);
/*
- * Copy over the virtio-scsi request header, which for a
- * ANY_LAYOUT enabled guest may span multiple iovecs, or a
- * single iovec may contain both the header + outgoing
- * WRITE payloads.
- *
- * copy_from_iter() will advance out_iter, so that it will
- * point at the start of the outgoing WRITE payload, if
- * DMA_TO_DEVICE is set.
+ * Validate the size of request and response buffers.
+ * Check for a sane response buffer so we can report
+ * early errors back to the guest.
*/
- iov_iter_init(&out_iter, WRITE, vq->iov, out, out_size);
+ ret = vhost_scsi_chk_size(vq, &vc);
+ if (ret)
+ goto err;
- if (unlikely(!copy_from_iter_full(req, req_size, &out_iter))) {
- vq_err(vq, "Faulted on copy_from_iter\n");
- vhost_scsi_send_bad_target(vs, vq, head, out);
- continue;
- }
- /* virtio-scsi spec requires byte 0 of the lun to be 1 */
- if (unlikely(*lunp != 1)) {
- vq_err(vq, "Illegal virtio-scsi lun: %u\n", *lunp);
- vhost_scsi_send_bad_target(vs, vq, head, out);
- continue;
- }
+ ret = vhost_scsi_get_req(vq, &vc, &tpg);
+ if (ret)
+ goto err;
+
+ ret = -EIO; /* bad target on any error from here on */
- tpg = READ_ONCE(vs_tpg[*target]);
- if (unlikely(!tpg)) {
- /* Target does not exist, fail the request */
- vhost_scsi_send_bad_target(vs, vq, head, out);
- continue;
- }
/*
* Determine data_direction by calculating the total outgoing
* iovec sizes + incoming iovec sizes vs. virtio-scsi request +
@@ -924,17 +995,17 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
*/
prot_bytes = 0;
- if (out_size > req_size) {
+ if (vc.out_size > vc.req_size) {
data_direction = DMA_TO_DEVICE;
- exp_data_len = out_size - req_size;
- data_iter = out_iter;
- } else if (in_size > rsp_size) {
+ exp_data_len = vc.out_size - vc.req_size;
+ data_iter = vc.out_iter;
+ } else if (vc.in_size > vc.rsp_size) {
data_direction = DMA_FROM_DEVICE;
- exp_data_len = in_size - rsp_size;
+ exp_data_len = vc.in_size - vc.rsp_size;
- iov_iter_init(&in_iter, READ, &vq->iov[out], in,
- rsp_size + exp_data_len);
- iov_iter_advance(&in_iter, rsp_size);
+ iov_iter_init(&in_iter, READ, &vq->iov[vc.out], vc.in,
+ vc.rsp_size + exp_data_len);
+ iov_iter_advance(&in_iter, vc.rsp_size);
data_iter = in_iter;
} else {
data_direction = DMA_NONE;
@@ -950,21 +1021,20 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
if (data_direction != DMA_TO_DEVICE) {
vq_err(vq, "Received non zero pi_bytesout,"
" but wrong data_direction\n");
- vhost_scsi_send_bad_target(vs, vq, head, out);
- continue;
+ goto err;
}
prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout);
} else if (v_req_pi.pi_bytesin) {
if (data_direction != DMA_FROM_DEVICE) {
vq_err(vq, "Received non zero pi_bytesin,"
" but wrong data_direction\n");
- vhost_scsi_send_bad_target(vs, vq, head, out);
- continue;
+ goto err;
}
prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin);
}
/*
- * Set prot_iter to data_iter, and advance past any
+ * Set prot_iter to data_iter and truncate it to
+ * prot_bytes, and advance data_iter past any
* preceeding prot_bytes that may be present.
*
* Also fix up the exp_data_len to reflect only the
@@ -973,6 +1043,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
if (prot_bytes) {
exp_data_len -= prot_bytes;
prot_iter = data_iter;
+ iov_iter_truncate(&prot_iter, prot_bytes);
iov_iter_advance(&data_iter, prot_bytes);
}
tag = vhost64_to_cpu(vq, v_req_pi.tag);
@@ -996,8 +1067,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
vq_err(vq, "Received SCSI CDB with command_size: %d that"
" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
scsi_command_size(cdb), VHOST_SCSI_MAX_CDB_SIZE);
- vhost_scsi_send_bad_target(vs, vq, head, out);
- continue;
+ goto err;
}
cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr,
exp_data_len + prot_bytes,
@@ -1005,13 +1075,12 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
if (IS_ERR(cmd)) {
vq_err(vq, "vhost_scsi_get_tag failed %ld\n",
PTR_ERR(cmd));
- vhost_scsi_send_bad_target(vs, vq, head, out);
- continue;
+ goto err;
}
cmd->tvc_vhost = vs;
cmd->tvc_vq = vq;
- cmd->tvc_resp_iov = vq->iov[out];
- cmd->tvc_in_iovs = in;
+ cmd->tvc_resp_iov = vq->iov[vc.out];
+ cmd->tvc_in_iovs = vc.in;
pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",
cmd->tvc_cdb[0], cmd->tvc_lun);
@@ -1019,14 +1088,12 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
" %d\n", cmd, exp_data_len, prot_bytes, data_direction);
if (data_direction != DMA_NONE) {
- ret = vhost_scsi_mapal(cmd,
- prot_bytes, &prot_iter,
- exp_data_len, &data_iter);
- if (unlikely(ret)) {
+ if (unlikely(vhost_scsi_mapal(cmd, prot_bytes,
+ &prot_iter, exp_data_len,
+ &data_iter))) {
vq_err(vq, "Failed to map iov to sgl\n");
vhost_scsi_release_cmd(&cmd->tvc_se_cmd);
- vhost_scsi_send_bad_target(vs, vq, head, out);
- continue;
+ goto err;
}
}
/*
@@ -1034,7 +1101,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
* complete the virtio-scsi request in TCM callback context via
* vhost_scsi_queue_data_in() and vhost_scsi_queue_status()
*/
- cmd->tvc_vq_desc = head;
+ cmd->tvc_vq_desc = vc.head;
/*
* Dispatch cmd descriptor for cmwq execution in process
* context provided by vhost_scsi_workqueue. This also ensures
@@ -1043,6 +1110,166 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
*/
INIT_WORK(&cmd->work, vhost_scsi_submission_work);
queue_work(vhost_scsi_workqueue, &cmd->work);
+ ret = 0;
+err:
+ /*
+ * ENXIO: No more requests, or read error, wait for next kick
+ * EINVAL: Invalid response buffer, drop the request
+ * EIO: Respond with bad target
+ * EAGAIN: Pending request
+ */
+ if (ret == -ENXIO)
+ break;
+ else if (ret == -EIO)
+ vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
+ }
+out:
+ mutex_unlock(&vq->mutex);
+}
+
+static void
+vhost_scsi_send_tmf_reject(struct vhost_scsi *vs,
+ struct vhost_virtqueue *vq,
+ struct vhost_scsi_ctx *vc)
+{
+ struct virtio_scsi_ctrl_tmf_resp __user *resp;
+ struct virtio_scsi_ctrl_tmf_resp rsp;
+ int ret;
+
+ pr_debug("%s\n", __func__);
+ memset(&rsp, 0, sizeof(rsp));
+ rsp.response = VIRTIO_SCSI_S_FUNCTION_REJECTED;
+ resp = vq->iov[vc->out].iov_base;
+ ret = __copy_to_user(resp, &rsp, sizeof(rsp));
+ if (!ret)
+ vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
+ else
+ pr_err("Faulted on virtio_scsi_ctrl_tmf_resp\n");
+}
+
+static void
+vhost_scsi_send_an_resp(struct vhost_scsi *vs,
+ struct vhost_virtqueue *vq,
+ struct vhost_scsi_ctx *vc)
+{
+ struct virtio_scsi_ctrl_an_resp __user *resp;
+ struct virtio_scsi_ctrl_an_resp rsp;
+ int ret;
+
+ pr_debug("%s\n", __func__);
+ memset(&rsp, 0, sizeof(rsp)); /* event_actual = 0 */
+ rsp.response = VIRTIO_SCSI_S_OK;
+ resp = vq->iov[vc->out].iov_base;
+ ret = __copy_to_user(resp, &rsp, sizeof(rsp));
+ if (!ret)
+ vhost_add_used_and_signal(&vs->dev, vq, vc->head, 0);
+ else
+ pr_err("Faulted on virtio_scsi_ctrl_an_resp\n");
+}
+
+static void
+vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq)
+{
+ union {
+ __virtio32 type;
+ struct virtio_scsi_ctrl_an_req an;
+ struct virtio_scsi_ctrl_tmf_req tmf;
+ } v_req;
+ struct vhost_scsi_ctx vc;
+ size_t typ_size;
+ int ret;
+
+ mutex_lock(&vq->mutex);
+ /*
+ * We can handle the vq only after the endpoint is setup by calling the
+ * VHOST_SCSI_SET_ENDPOINT ioctl.
+ */
+ if (!vq->private_data)
+ goto out;
+
+ memset(&vc, 0, sizeof(vc));
+
+ vhost_disable_notify(&vs->dev, vq);
+
+ for (;;) {
+ ret = vhost_scsi_get_desc(vs, vq, &vc);
+ if (ret)
+ goto err;
+
+ /*
+ * Get the request type first in order to setup
+ * other parameters dependent on the type.
+ */
+ vc.req = &v_req.type;
+ typ_size = sizeof(v_req.type);
+
+ if (unlikely(!copy_from_iter_full(vc.req, typ_size,
+ &vc.out_iter))) {
+ vq_err(vq, "Faulted on copy_from_iter tmf type\n");
+ /*
+ * The size of the response buffer depends on the
+ * request type and must be validated against it.
+ * Since the request type is not known, don't send
+ * a response.
+ */
+ continue;
+ }
+
+ switch (v_req.type) {
+ case VIRTIO_SCSI_T_TMF:
+ vc.req = &v_req.tmf;
+ vc.req_size = sizeof(struct virtio_scsi_ctrl_tmf_req);
+ vc.rsp_size = sizeof(struct virtio_scsi_ctrl_tmf_resp);
+ vc.lunp = &v_req.tmf.lun[0];
+ vc.target = &v_req.tmf.lun[1];
+ break;
+ case VIRTIO_SCSI_T_AN_QUERY:
+ case VIRTIO_SCSI_T_AN_SUBSCRIBE:
+ vc.req = &v_req.an;
+ vc.req_size = sizeof(struct virtio_scsi_ctrl_an_req);
+ vc.rsp_size = sizeof(struct virtio_scsi_ctrl_an_resp);
+ vc.lunp = &v_req.an.lun[0];
+ vc.target = NULL;
+ break;
+ default:
+ vq_err(vq, "Unknown control request %d", v_req.type);
+ continue;
+ }
+
+ /*
+ * Validate the size of request and response buffers.
+ * Check for a sane response buffer so we can report
+ * early errors back to the guest.
+ */
+ ret = vhost_scsi_chk_size(vq, &vc);
+ if (ret)
+ goto err;
+
+ /*
+ * Get the rest of the request now that its size is known.
+ */
+ vc.req += typ_size;
+ vc.req_size -= typ_size;
+
+ ret = vhost_scsi_get_req(vq, &vc, NULL);
+ if (ret)
+ goto err;
+
+ if (v_req.type == VIRTIO_SCSI_T_TMF)
+ vhost_scsi_send_tmf_reject(vs, vq, &vc);
+ else
+ vhost_scsi_send_an_resp(vs, vq, &vc);
+err:
+ /*
+ * ENXIO: No more requests, or read error, wait for next kick
+ * EINVAL: Invalid response buffer, drop the request
+ * EIO: Respond with bad target
+ * EAGAIN: Pending request
+ */
+ if (ret == -ENXIO)
+ break;
+ else if (ret == -EIO)
+ vhost_scsi_send_bad_target(vs, vq, vc.head, vc.out);
}
out:
mutex_unlock(&vq->mutex);
@@ -1050,7 +1277,12 @@ out:
static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
{
+ struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
+ poll.work);
+ struct vhost_scsi *vs = container_of(vq->dev, struct vhost_scsi, dev);
+
pr_debug("%s: The handling func for control queue.\n", __func__);
+ vhost_scsi_ctl_handle_vq(vs, vq);
}
static void
diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
index d1c1f6283729..728ecd1eea30 100644
--- a/drivers/virtio/virtio_balloon.c
+++ b/drivers/virtio/virtio_balloon.c
@@ -41,13 +41,34 @@
#define VIRTIO_BALLOON_ARRAY_PFNS_MAX 256
#define VIRTBALLOON_OOM_NOTIFY_PRIORITY 80
+#define VIRTIO_BALLOON_FREE_PAGE_ALLOC_FLAG (__GFP_NORETRY | __GFP_NOWARN | \
+ __GFP_NOMEMALLOC)
+/* The order of free page blocks to report to host */
+#define VIRTIO_BALLOON_FREE_PAGE_ORDER (MAX_ORDER - 1)
+/* The size of a free page block in bytes */
+#define VIRTIO_BALLOON_FREE_PAGE_SIZE \
+ (1 << (VIRTIO_BALLOON_FREE_PAGE_ORDER + PAGE_SHIFT))
+
#ifdef CONFIG_BALLOON_COMPACTION
static struct vfsmount *balloon_mnt;
#endif
+enum virtio_balloon_vq {
+ VIRTIO_BALLOON_VQ_INFLATE,
+ VIRTIO_BALLOON_VQ_DEFLATE,
+ VIRTIO_BALLOON_VQ_STATS,
+ VIRTIO_BALLOON_VQ_FREE_PAGE,
+ VIRTIO_BALLOON_VQ_MAX
+};
+
struct virtio_balloon {
struct virtio_device *vdev;
- struct virtqueue *inflate_vq, *deflate_vq, *stats_vq;
+ struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *free_page_vq;
+
+ /* Balloon's own wq for cpu-intensive work items */
+ struct workqueue_struct *balloon_wq;
+ /* The free page reporting work item submitted to the balloon wq */
+ struct work_struct report_free_page_work;
/* The balloon servicing is delegated to a freezable workqueue. */
struct work_struct update_balloon_stats_work;
@@ -57,6 +78,18 @@ struct virtio_balloon {
spinlock_t stop_update_lock;
bool stop_update;
+ /* The list of allocated free pages, waiting to be given back to mm */
+ struct list_head free_page_list;
+ spinlock_t free_page_list_lock;
+ /* The number of free page blocks on the above list */
+ unsigned long num_free_page_blocks;
+ /* The cmd id received from host */
+ u32 cmd_id_received;
+ /* The cmd id that is actively in use */
+ __virtio32 cmd_id_active;
+ /* Buffer to store the stop sign */
+ __virtio32 cmd_id_stop;
+
/* Waiting for host to ack the pages we released. */
wait_queue_head_t acked;
@@ -320,17 +353,6 @@ static void stats_handle_request(struct virtio_balloon *vb)
virtqueue_kick(vq);
}
-static void virtballoon_changed(struct virtio_device *vdev)
-{
- struct virtio_balloon *vb = vdev->priv;
- unsigned long flags;
-
- spin_lock_irqsave(&vb->stop_update_lock, flags);
- if (!vb->stop_update)
- queue_work(system_freezable_wq, &vb->update_balloon_size_work);
- spin_unlock_irqrestore(&vb->stop_update_lock, flags);
-}
-
static inline s64 towards_target(struct virtio_balloon *vb)
{
s64 target;
@@ -347,6 +369,60 @@ static inline s64 towards_target(struct virtio_balloon *vb)
return target - vb->num_pages;
}
+/* Gives back @num_to_return blocks of free pages to mm. */
+static unsigned long return_free_pages_to_mm(struct virtio_balloon *vb,
+ unsigned long num_to_return)
+{
+ struct page *page;
+ unsigned long num_returned;
+
+ spin_lock_irq(&vb->free_page_list_lock);
+ for (num_returned = 0; num_returned < num_to_return; num_returned++) {
+ page = balloon_page_pop(&vb->free_page_list);
+ if (!page)
+ break;
+ free_pages((unsigned long)page_address(page),
+ VIRTIO_BALLOON_FREE_PAGE_ORDER);
+ }
+ vb->num_free_page_blocks -= num_returned;
+ spin_unlock_irq(&vb->free_page_list_lock);
+
+ return num_returned;
+}
+
+static void virtballoon_changed(struct virtio_device *vdev)
+{
+ struct virtio_balloon *vb = vdev->priv;
+ unsigned long flags;
+ s64 diff = towards_target(vb);
+
+ if (diff) {
+ spin_lock_irqsave(&vb->stop_update_lock, flags);
+ if (!vb->stop_update)
+ queue_work(system_freezable_wq,
+ &vb->update_balloon_size_work);
+ spin_unlock_irqrestore(&vb->stop_update_lock, flags);
+ }
+
+ if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
+ virtio_cread(vdev, struct virtio_balloon_config,
+ free_page_report_cmd_id, &vb->cmd_id_received);
+ if (vb->cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
+ /* Pass ULONG_MAX to give back all the free pages */
+ return_free_pages_to_mm(vb, ULONG_MAX);
+ } else if (vb->cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
+ vb->cmd_id_received !=
+ virtio32_to_cpu(vdev, vb->cmd_id_active)) {
+ spin_lock_irqsave(&vb->stop_update_lock, flags);
+ if (!vb->stop_update) {
+ queue_work(vb->balloon_wq,
+ &vb->report_free_page_work);
+ }
+ spin_unlock_irqrestore(&vb->stop_update_lock, flags);
+ }
+ }
+}
+
static void update_balloon_size(struct virtio_balloon *vb)
{
u32 actual = vb->num_pages;
@@ -389,26 +465,44 @@ static void update_balloon_size_func(struct work_struct *work)
static int init_vqs(struct virtio_balloon *vb)
{
- struct virtqueue *vqs[3];
- vq_callback_t *callbacks[] = { balloon_ack, balloon_ack, stats_request };
- static const char * const names[] = { "inflate", "deflate", "stats" };
- int err, nvqs;
+ struct virtqueue *vqs[VIRTIO_BALLOON_VQ_MAX];
+ vq_callback_t *callbacks[VIRTIO_BALLOON_VQ_MAX];
+ const char *names[VIRTIO_BALLOON_VQ_MAX];
+ int err;
/*
- * We expect two virtqueues: inflate and deflate, and
- * optionally stat.
+ * Inflateq and deflateq are used unconditionally. The names[]
+ * will be NULL if the related feature is not enabled, which will
+ * cause no allocation for the corresponding virtqueue in find_vqs.
*/
- nvqs = virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ) ? 3 : 2;
- err = virtio_find_vqs(vb->vdev, nvqs, vqs, callbacks, names, NULL);
+ callbacks[VIRTIO_BALLOON_VQ_INFLATE] = balloon_ack;
+ names[VIRTIO_BALLOON_VQ_INFLATE] = "inflate";
+ callbacks[VIRTIO_BALLOON_VQ_DEFLATE] = balloon_ack;
+ names[VIRTIO_BALLOON_VQ_DEFLATE] = "deflate";
+ names[VIRTIO_BALLOON_VQ_STATS] = NULL;
+ names[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
+
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
+ names[VIRTIO_BALLOON_VQ_STATS] = "stats";
+ callbacks[VIRTIO_BALLOON_VQ_STATS] = stats_request;
+ }
+
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
+ names[VIRTIO_BALLOON_VQ_FREE_PAGE] = "free_page_vq";
+ callbacks[VIRTIO_BALLOON_VQ_FREE_PAGE] = NULL;
+ }
+
+ err = vb->vdev->config->find_vqs(vb->vdev, VIRTIO_BALLOON_VQ_MAX,
+ vqs, callbacks, names, NULL, NULL);
if (err)
return err;
- vb->inflate_vq = vqs[0];
- vb->deflate_vq = vqs[1];
+ vb->inflate_vq = vqs[VIRTIO_BALLOON_VQ_INFLATE];
+ vb->deflate_vq = vqs[VIRTIO_BALLOON_VQ_DEFLATE];
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_STATS_VQ)) {
struct scatterlist sg;
unsigned int num_stats;
- vb->stats_vq = vqs[2];
+ vb->stats_vq = vqs[VIRTIO_BALLOON_VQ_STATS];
/*
* Prime this virtqueue with one buffer so the hypervisor can
@@ -426,9 +520,145 @@ static int init_vqs(struct virtio_balloon *vb)
}
virtqueue_kick(vb->stats_vq);
}
+
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
+ vb->free_page_vq = vqs[VIRTIO_BALLOON_VQ_FREE_PAGE];
+
+ return 0;
+}
+
+static int send_cmd_id_start(struct virtio_balloon *vb)
+{
+ struct scatterlist sg;
+ struct virtqueue *vq = vb->free_page_vq;
+ int err, unused;
+
+ /* Detach all the used buffers from the vq */
+ while (virtqueue_get_buf(vq, &unused))
+ ;
+
+ vb->cmd_id_active = cpu_to_virtio32(vb->vdev, vb->cmd_id_received);
+ sg_init_one(&sg, &vb->cmd_id_active, sizeof(vb->cmd_id_active));
+ err = virtqueue_add_outbuf(vq, &sg, 1, &vb->cmd_id_active, GFP_KERNEL);
+ if (!err)
+ virtqueue_kick(vq);
+ return err;
+}
+
+static int send_cmd_id_stop(struct virtio_balloon *vb)
+{
+ struct scatterlist sg;
+ struct virtqueue *vq = vb->free_page_vq;
+ int err, unused;
+
+ /* Detach all the used buffers from the vq */
+ while (virtqueue_get_buf(vq, &unused))
+ ;
+
+ sg_init_one(&sg, &vb->cmd_id_stop, sizeof(vb->cmd_id_stop));
+ err = virtqueue_add_outbuf(vq, &sg, 1, &vb->cmd_id_stop, GFP_KERNEL);
+ if (!err)
+ virtqueue_kick(vq);
+ return err;
+}
+
+static int get_free_page_and_send(struct virtio_balloon *vb)
+{
+ struct virtqueue *vq = vb->free_page_vq;
+ struct page *page;
+ struct scatterlist sg;
+ int err, unused;
+ void *p;
+
+ /* Detach all the used buffers from the vq */
+ while (virtqueue_get_buf(vq, &unused))
+ ;
+
+ page = alloc_pages(VIRTIO_BALLOON_FREE_PAGE_ALLOC_FLAG,
+ VIRTIO_BALLOON_FREE_PAGE_ORDER);
+ /*
+ * When the allocation returns NULL, it indicates that we have got all
+ * the possible free pages, so return -EINTR to stop.
+ */
+ if (!page)
+ return -EINTR;
+
+ p = page_address(page);
+ sg_init_one(&sg, p, VIRTIO_BALLOON_FREE_PAGE_SIZE);
+ /* There is always 1 entry reserved for the cmd id to use. */
+ if (vq->num_free > 1) {
+ err = virtqueue_add_inbuf(vq, &sg, 1, p, GFP_KERNEL);
+ if (unlikely(err)) {
+ free_pages((unsigned long)p,
+ VIRTIO_BALLOON_FREE_PAGE_ORDER);
+ return err;
+ }
+ virtqueue_kick(vq);
+ spin_lock_irq(&vb->free_page_list_lock);
+ balloon_page_push(&vb->free_page_list, page);
+ vb->num_free_page_blocks++;
+ spin_unlock_irq(&vb->free_page_list_lock);
+ } else {
+ /*
+ * The vq has no available entry to add this page block, so
+ * just free it.
+ */
+ free_pages((unsigned long)p, VIRTIO_BALLOON_FREE_PAGE_ORDER);
+ }
+
+ return 0;
+}
+
+static int send_free_pages(struct virtio_balloon *vb)
+{
+ int err;
+ u32 cmd_id_active;
+
+ while (1) {
+ /*
+ * If a stop id or a new cmd id was just received from host,
+ * stop the reporting.
+ */
+ cmd_id_active = virtio32_to_cpu(vb->vdev, vb->cmd_id_active);
+ if (cmd_id_active != vb->cmd_id_received)
+ break;
+
+ /*
+ * The free page blocks are allocated and sent to host one by
+ * one.
+ */
+ err = get_free_page_and_send(vb);
+ if (err == -EINTR)
+ break;
+ else if (unlikely(err))
+ return err;
+ }
+
return 0;
}
+static void report_free_page_func(struct work_struct *work)
+{
+ int err;
+ struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
+ report_free_page_work);
+ struct device *dev = &vb->vdev->dev;
+
+ /* Start by sending the received cmd id to host with an outbuf. */
+ err = send_cmd_id_start(vb);
+ if (unlikely(err))
+ dev_err(dev, "Failed to send a start id, err = %d\n", err);
+
+ err = send_free_pages(vb);
+ if (unlikely(err))
+ dev_err(dev, "Failed to send a free page, err = %d\n", err);
+
+ /* End by sending a stop id to host with an outbuf. */
+ err = send_cmd_id_stop(vb);
+ if (unlikely(err))
+ dev_err(dev, "Failed to send a stop id, err = %d\n", err);
+}
+
#ifdef CONFIG_BALLOON_COMPACTION
/*
* virtballoon_migratepage - perform the balloon page migration on behalf of
@@ -512,14 +742,23 @@ static struct file_system_type balloon_fs = {
#endif /* CONFIG_BALLOON_COMPACTION */
-static unsigned long virtio_balloon_shrinker_scan(struct shrinker *shrinker,
- struct shrink_control *sc)
+static unsigned long shrink_free_pages(struct virtio_balloon *vb,
+ unsigned long pages_to_free)
{
- unsigned long pages_to_free, pages_freed = 0;
- struct virtio_balloon *vb = container_of(shrinker,
- struct virtio_balloon, shrinker);
+ unsigned long blocks_to_free, blocks_freed;
- pages_to_free = sc->nr_to_scan * VIRTIO_BALLOON_PAGES_PER_PAGE;
+ pages_to_free = round_up(pages_to_free,
+ 1 << VIRTIO_BALLOON_FREE_PAGE_ORDER);
+ blocks_to_free = pages_to_free >> VIRTIO_BALLOON_FREE_PAGE_ORDER;
+ blocks_freed = return_free_pages_to_mm(vb, blocks_to_free);
+
+ return blocks_freed << VIRTIO_BALLOON_FREE_PAGE_ORDER;
+}
+
+static unsigned long shrink_balloon_pages(struct virtio_balloon *vb,
+ unsigned long pages_to_free)
+{
+ unsigned long pages_freed = 0;
/*
* One invocation of leak_balloon can deflate at most
@@ -527,12 +766,33 @@ static unsigned long virtio_balloon_shrinker_scan(struct shrinker *shrinker,
* multiple times to deflate pages till reaching pages_to_free.
*/
while (vb->num_pages && pages_to_free) {
+ pages_freed += leak_balloon(vb, pages_to_free) /
+ VIRTIO_BALLOON_PAGES_PER_PAGE;
pages_to_free -= pages_freed;
- pages_freed += leak_balloon(vb, pages_to_free);
}
update_balloon_size(vb);
- return pages_freed / VIRTIO_BALLOON_PAGES_PER_PAGE;
+ return pages_freed;
+}
+
+static unsigned long virtio_balloon_shrinker_scan(struct shrinker *shrinker,
+ struct shrink_control *sc)
+{
+ unsigned long pages_to_free, pages_freed = 0;
+ struct virtio_balloon *vb = container_of(shrinker,
+ struct virtio_balloon, shrinker);
+
+ pages_to_free = sc->nr_to_scan * VIRTIO_BALLOON_PAGES_PER_PAGE;
+
+ if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
+ pages_freed = shrink_free_pages(vb, pages_to_free);
+
+ if (pages_freed >= pages_to_free)
+ return pages_freed;
+
+ pages_freed += shrink_balloon_pages(vb, pages_to_free - pages_freed);
+
+ return pages_freed;
}
static unsigned long virtio_balloon_shrinker_count(struct shrinker *shrinker,
@@ -540,8 +800,12 @@ static unsigned long virtio_balloon_shrinker_count(struct shrinker *shrinker,
{
struct virtio_balloon *vb = container_of(shrinker,
struct virtio_balloon, shrinker);
+ unsigned long count;
- return vb->num_pages / VIRTIO_BALLOON_PAGES_PER_PAGE;
+ count = vb->num_pages / VIRTIO_BALLOON_PAGES_PER_PAGE;
+ count += vb->num_free_page_blocks >> VIRTIO_BALLOON_FREE_PAGE_ORDER;
+
+ return count;
}
static void virtio_balloon_unregister_shrinker(struct virtio_balloon *vb)
@@ -561,6 +825,7 @@ static int virtio_balloon_register_shrinker(struct virtio_balloon *vb)
static int virtballoon_probe(struct virtio_device *vdev)
{
struct virtio_balloon *vb;
+ __u32 poison_val;
int err;
if (!vdev->config->get) {
@@ -604,6 +869,36 @@ static int virtballoon_probe(struct virtio_device *vdev)
}
vb->vb_dev_info.inode->i_mapping->a_ops = &balloon_aops;
#endif
+ if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
+ /*
+ * There is always one entry reserved for cmd id, so the ring
+ * size needs to be at least two to report free page hints.
+ */
+ if (virtqueue_get_vring_size(vb->free_page_vq) < 2) {
+ err = -ENOSPC;
+ goto out_del_vqs;
+ }
+ vb->balloon_wq = alloc_workqueue("balloon-wq",
+ WQ_FREEZABLE | WQ_CPU_INTENSIVE, 0);
+ if (!vb->balloon_wq) {
+ err = -ENOMEM;
+ goto out_del_vqs;
+ }
+ INIT_WORK(&vb->report_free_page_work, report_free_page_func);
+ vb->cmd_id_received = VIRTIO_BALLOON_CMD_ID_STOP;
+ vb->cmd_id_active = cpu_to_virtio32(vb->vdev,
+ VIRTIO_BALLOON_CMD_ID_STOP);
+ vb->cmd_id_stop = cpu_to_virtio32(vb->vdev,
+ VIRTIO_BALLOON_CMD_ID_STOP);
+ vb->num_free_page_blocks = 0;
+ spin_lock_init(&vb->free_page_list_lock);
+ INIT_LIST_HEAD(&vb->free_page_list);
+ if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_PAGE_POISON)) {
+ memset(&poison_val, PAGE_POISON, sizeof(poison_val));
+ virtio_cwrite(vb->vdev, struct virtio_balloon_config,
+ poison_val, &poison_val);
+ }
+ }
/*
* We continue to use VIRTIO_BALLOON_F_DEFLATE_ON_OOM to decide if a
* shrinker needs to be registered to relieve memory pressure.
@@ -611,7 +906,7 @@ static int virtballoon_probe(struct virtio_device *vdev)
if (virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_DEFLATE_ON_OOM)) {
err = virtio_balloon_register_shrinker(vb);
if (err)
- goto out_del_vqs;
+ goto out_del_balloon_wq;
}
virtio_device_ready(vdev);
@@ -619,6 +914,9 @@ static int virtballoon_probe(struct virtio_device *vdev)
virtballoon_changed(vdev);
return 0;
+out_del_balloon_wq:
+ if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
+ destroy_workqueue(vb->balloon_wq);
out_del_vqs:
vdev->config->del_vqs(vdev);
out_free_vb:
@@ -652,6 +950,11 @@ static void virtballoon_remove(struct virtio_device *vdev)
cancel_work_sync(&vb->update_balloon_size_work);
cancel_work_sync(&vb->update_balloon_stats_work);
+ if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
+ cancel_work_sync(&vb->report_free_page_work);
+ destroy_workqueue(vb->balloon_wq);
+ }
+
remove_common(vb);
#ifdef CONFIG_BALLOON_COMPACTION
if (vb->vb_dev_info.inode)
@@ -695,6 +998,9 @@ static int virtballoon_restore(struct virtio_device *vdev)
static int virtballoon_validate(struct virtio_device *vdev)
{
+ if (!page_poisoning_enabled())
+ __virtio_clear_bit(vdev, VIRTIO_BALLOON_F_PAGE_POISON);
+
__virtio_clear_bit(vdev, VIRTIO_F_IOMMU_PLATFORM);
return 0;
}
@@ -703,6 +1009,8 @@ static unsigned int features[] = {
VIRTIO_BALLOON_F_MUST_TELL_HOST,
VIRTIO_BALLOON_F_STATS_VQ,
VIRTIO_BALLOON_F_DEFLATE_ON_OOM,
+ VIRTIO_BALLOON_F_FREE_PAGE_HINT,
+ VIRTIO_BALLOON_F_PAGE_POISON,
};
static struct virtio_driver virtio_balloon_driver = {
diff --git a/include/uapi/linux/virtio_balloon.h b/include/uapi/linux/virtio_balloon.h
index 13b8cb563892..a1966cd7b677 100644
--- a/include/uapi/linux/virtio_balloon.h
+++ b/include/uapi/linux/virtio_balloon.h
@@ -34,15 +34,23 @@
#define VIRTIO_BALLOON_F_MUST_TELL_HOST 0 /* Tell before reclaiming pages */
#define VIRTIO_BALLOON_F_STATS_VQ 1 /* Memory Stats virtqueue */
#define VIRTIO_BALLOON_F_DEFLATE_ON_OOM 2 /* Deflate balloon on OOM */
+#define VIRTIO_BALLOON_F_FREE_PAGE_HINT 3 /* VQ to report free pages */
+#define VIRTIO_BALLOON_F_PAGE_POISON 4 /* Guest is using page poisoning */
/* Size of a PFN in the balloon interface. */
#define VIRTIO_BALLOON_PFN_SHIFT 12
+#define VIRTIO_BALLOON_CMD_ID_STOP 0
+#define VIRTIO_BALLOON_CMD_ID_DONE 1
struct virtio_balloon_config {
/* Number of pages host wants Guest to give up. */
__u32 num_pages;
/* Number of pages we've actually got in balloon. */
__u32 actual;
+ /* Free page report command id, readonly by guest */
+ __u32 free_page_report_cmd_id;
+ /* Stores PAGE_POISON if page poisoning is in use */
+ __u32 poison_val;
};
#define VIRTIO_BALLOON_S_SWAP_IN 0 /* Amount of memory swapped in */
diff --git a/kernel/configs/kvm_guest.config b/kernel/configs/kvm_guest.config
index 108fecc20fc1..208481d91090 100644
--- a/kernel/configs/kvm_guest.config
+++ b/kernel/configs/kvm_guest.config
@@ -20,6 +20,7 @@ CONFIG_PARAVIRT=y
CONFIG_KVM_GUEST=y
CONFIG_S390_GUEST=y
CONFIG_VIRTIO=y
+CONFIG_VIRTIO_MENU=y
CONFIG_VIRTIO_PCI=y
CONFIG_VIRTIO_BLK=y
CONFIG_VIRTIO_CONSOLE=y
diff --git a/mm/page_poison.c b/mm/page_poison.c
index f7e2a676365a..f0c15e9017c0 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -17,6 +17,11 @@ static int __init early_page_poison_param(char *buf)
}
early_param("page_poison", early_page_poison_param);
+/**
+ * page_poisoning_enabled - check if page poisoning is enabled
+ *
+ * Return true if page poisoning is enabled, or false if not.
+ */
bool page_poisoning_enabled(void)
{
/*
@@ -29,6 +34,7 @@ bool page_poisoning_enabled(void)
(!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
debug_pagealloc_enabled()));
}
+EXPORT_SYMBOL_GPL(page_poisoning_enabled);
static void poison_page(struct page *page)
{