Differential D19495 Diff 58265 usr.sbin/bhyve/block_if.c

Changeset View

Standalone View

usr.sbin/bhyve/block_if.c

Show First 20 Lines • Show All 51 Lines • ▼ Show 20 Lines
#include <string.h>		#include <string.h>
#include <pthread.h>		#include <pthread.h>
#include <pthread_np.h>		#include <pthread_np.h>
#include <signal.h>		#include <signal.h>
#include <sysexits.h>		#include <sysexits.h>
#include <unistd.h>		#include <unistd.h>

#include <machine/atomic.h>		#include <machine/atomic.h>
		#include <machine/vmm_snapshot.h>

#include "bhyverun.h"		#include "bhyverun.h"
#include "mevent.h"		#include "mevent.h"
#include "block_if.h"		#include "block_if.h"

#define BLOCKIF_SIG 0xb109b109		#define BLOCKIF_SIG 0xb109b109

#define BLOCKIF_NUMTHR 8		#define BLOCKIF_NUMTHR 8
#define BLOCKIF_MAXREQ (64 + BLOCKIF_NUMTHR)		#define BLOCKIF_MAXREQ (64 + BLOCKIF_NUMTHR)

		#define NO_THREAD_IDX (-2)
		#define REQ_IDX_SEPARATOR (-1)

enum blockop {		enum blockop {
BOP_READ,		BOP_READ,
BOP_WRITE,		BOP_WRITE,
BOP_FLUSH,		BOP_FLUSH,
BOP_DELETE		BOP_DELETE
};		};

enum blockstat {		enum blockstat {
Show All 20 Lines	struct blockif_ctxt {
int bc_isgeom;		int bc_isgeom;
int bc_candelete;		int bc_candelete;
int bc_rdonly;		int bc_rdonly;
off_t bc_size;		off_t bc_size;
int bc_sectsz;		int bc_sectsz;
int bc_psectsz;		int bc_psectsz;
int bc_psectoff;		int bc_psectoff;
int bc_closing;		int bc_closing;
		int bc_paused;
		int bc_work_count;
pthread_t bc_btid[BLOCKIF_NUMTHR];		pthread_t bc_btid[BLOCKIF_NUMTHR];
pthread_mutex_t bc_mtx;		pthread_mutex_t bc_mtx;
pthread_cond_t bc_cond;		pthread_cond_t bc_cond;
		pthread_cond_t bc_paused_cond;
		pthread_cond_t bc_work_done_cond;

/* Request elements and free/pending/busy queues */		/* Request elements and free/pending/busy queues */
TAILQ_HEAD(, blockif_elem) bc_freeq;		TAILQ_HEAD(, blockif_elem) bc_freeq;
TAILQ_HEAD(, blockif_elem) bc_pendq;		TAILQ_HEAD(, blockif_elem) bc_pendq;
TAILQ_HEAD(, blockif_elem) bc_busyq;		TAILQ_HEAD(, blockif_elem) bc_busyq;
struct blockif_elem bc_reqs[BLOCKIF_MAXREQ];		struct blockif_elem bc_reqs[BLOCKIF_MAXREQ];
};		};

▲ Show 20 Lines • Show All 86 Lines • ▼ Show 20 Lines	if (tbe->be_req->br_offset == be->be_block)
tbe->be_status = BST_PEND;		tbe->be_status = BST_PEND;
}		}
be->be_tid = 0;		be->be_tid = 0;
be->be_status = BST_FREE;		be->be_status = BST_FREE;
be->be_req = NULL;		be->be_req = NULL;
TAILQ_INSERT_TAIL(&bc->bc_freeq, be, be_link);		TAILQ_INSERT_TAIL(&bc->bc_freeq, be, be_link);
}		}

		static int
		blockif_flush_bc(struct blockif_ctxt *bc)
		{
		if (bc->bc_ischr) {
		if (ioctl(bc->bc_fd, DIOCGFLUSH))
		return (errno);
		} else if (fsync(bc->bc_fd))
		return (errno);

		return (0);
		}

static void		static void
blockif_proc(struct blockif_ctxt bc, struct blockif_elem be, uint8_t *buf)		blockif_proc(struct blockif_ctxt bc, struct blockif_elem be, uint8_t *buf)
{		{
struct blockif_req *br;		struct blockif_req *br;
off_t arg[2];		off_t arg[2];
ssize_t clen, len, off, boff, voff;		ssize_t clen, len, off, boff, voff;
int i, err;		int i, err;

▲ Show 20 Lines • Show All 74 Lines • ▼ Show 20 Lines	while (br->br_resid > 0) {
err = errno;		err = errno;
break;		break;
}		}
off += len;		off += len;
br->br_resid -= len;		br->br_resid -= len;
}		}
break;		break;
case BOP_FLUSH:		case BOP_FLUSH:
if (bc->bc_ischr) {		err = blockif_flush_bc(bc);
if (ioctl(bc->bc_fd, DIOCGFLUSH))
err = errno;
} else if (fsync(bc->bc_fd))
err = errno;
break;		break;
case BOP_DELETE:		case BOP_DELETE:
if (!bc->bc_candelete)		if (!bc->bc_candelete)
err = EOPNOTSUPP;		err = EOPNOTSUPP;
else if (bc->bc_rdonly)		else if (bc->bc_rdonly)
err = EROFS;		err = EROFS;
else if (bc->bc_ischr) {		else if (bc->bc_ischr) {
arg[0] = br->br_offset;		arg[0] = br->br_offset;
Show All 27 Lines	blockif_thr(void *arg)
if (bc->bc_isgeom)		if (bc->bc_isgeom)
buf = malloc(MAXPHYS);		buf = malloc(MAXPHYS);
else		else
buf = NULL;		buf = NULL;
t = pthread_self();		t = pthread_self();

pthread_mutex_lock(&bc->bc_mtx);		pthread_mutex_lock(&bc->bc_mtx);
for (;;) {		for (;;) {
while (blockif_dequeue(bc, t, &be)) {		bc->bc_work_count++;

		/* We cannot process work if the interface is paused */
		while (!bc->bc_paused && blockif_dequeue(bc, t, &be)) {
pthread_mutex_unlock(&bc->bc_mtx);		pthread_mutex_unlock(&bc->bc_mtx);
blockif_proc(bc, be, buf);		blockif_proc(bc, be, buf);
pthread_mutex_lock(&bc->bc_mtx);		pthread_mutex_lock(&bc->bc_mtx);
blockif_complete(bc, be);		blockif_complete(bc, be);
}		}
/* Check ctxt status here to see if exit requested */
		bc->bc_work_count--;

		/* If none of the workers is busy, notify the main thread */
		if (bc->bc_work_count == 0)
		pthread_cond_broadcast(&bc->bc_work_done_cond);

		/*
		* Check ctxt status here to see if exit requested
		*
		* No sense to wait while paused if closing anyway
		*/
if (bc->bc_closing)		if (bc->bc_closing)
break;		break;

		/* Make all worker threads wait here if the device is paused */
		while (bc->bc_paused)
		pthread_cond_wait(&bc->bc_paused_cond, &bc->bc_mtx);

pthread_cond_wait(&bc->bc_cond, &bc->bc_mtx);		pthread_cond_wait(&bc->bc_cond, &bc->bc_mtx);
}		}
pthread_mutex_unlock(&bc->bc_mtx);		pthread_mutex_unlock(&bc->bc_mtx);

if (buf)		if (buf)
free(buf);		free(buf);
pthread_exit(NULL);		pthread_exit(NULL);
return (NULL);		return (NULL);
▲ Show 20 Lines • Show All 187 Lines • ▼ Show 20 Lines	#endif
bc->bc_candelete = candelete;		bc->bc_candelete = candelete;
bc->bc_rdonly = ro;		bc->bc_rdonly = ro;
bc->bc_size = size;		bc->bc_size = size;
bc->bc_sectsz = sectsz;		bc->bc_sectsz = sectsz;
bc->bc_psectsz = psectsz;		bc->bc_psectsz = psectsz;
bc->bc_psectoff = psectoff;		bc->bc_psectoff = psectoff;
pthread_mutex_init(&bc->bc_mtx, NULL);		pthread_mutex_init(&bc->bc_mtx, NULL);
pthread_cond_init(&bc->bc_cond, NULL);		pthread_cond_init(&bc->bc_cond, NULL);
		bc->bc_paused = 0;
		bc->bc_work_count = 0;
		pthread_cond_init(&bc->bc_paused_cond, NULL);
		pthread_cond_init(&bc->bc_work_done_cond, NULL);
TAILQ_INIT(&bc->bc_freeq);		TAILQ_INIT(&bc->bc_freeq);
TAILQ_INIT(&bc->bc_pendq);		TAILQ_INIT(&bc->bc_pendq);
TAILQ_INIT(&bc->bc_busyq);		TAILQ_INIT(&bc->bc_busyq);
for (i = 0; i < BLOCKIF_MAXREQ; i++) {		for (i = 0; i < BLOCKIF_MAXREQ; i++) {
bc->bc_reqs[i].be_status = BST_FREE;		bc->bc_reqs[i].be_status = BST_FREE;
TAILQ_INSERT_HEAD(&bc->bc_freeq, &bc->bc_reqs[i], be_link);		TAILQ_INSERT_HEAD(&bc->bc_freeq, &bc->bc_reqs[i], be_link);
}		}

Show All 15 Lines
blockif_request(struct blockif_ctxt bc, struct blockif_req breq,		blockif_request(struct blockif_ctxt bc, struct blockif_req breq,
enum blockop op)		enum blockop op)
{		{
int err;		int err;

err = 0;		err = 0;

pthread_mutex_lock(&bc->bc_mtx);		pthread_mutex_lock(&bc->bc_mtx);
		/* should make thread wait if interface paused ? */
if (!TAILQ_EMPTY(&bc->bc_freeq)) {		if (!TAILQ_EMPTY(&bc->bc_freeq)) {
/*		/*
* Enqueue and inform the block i/o thread		* Enqueue and inform the block i/o thread
* that there is work available		* that there is work available
*/		*/
if (blockif_enqueue(bc, breq, op))		if (blockif_enqueue(bc, breq, op))
pthread_cond_signal(&bc->bc_cond);		pthread_cond_signal(&bc->bc_cond);
} else {		} else {
▲ Show 20 Lines • Show All 45 Lines • ▼ Show 20 Lines
int		int
blockif_cancel(struct blockif_ctxt bc, struct blockif_req breq)		blockif_cancel(struct blockif_ctxt bc, struct blockif_req breq)
{		{
struct blockif_elem *be;		struct blockif_elem *be;

assert(bc->bc_magic == BLOCKIF_SIG);		assert(bc->bc_magic == BLOCKIF_SIG);

pthread_mutex_lock(&bc->bc_mtx);		pthread_mutex_lock(&bc->bc_mtx);
		/* XXX: not waiting while paused */

/*		/*
* Check pending requests.		* Check pending requests.
*/		*/
TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {		TAILQ_FOREACH(be, &bc->bc_pendq, be_link) {
if (be->be_req == breq)		if (be->be_req == breq)
break;		break;
}		}
if (be != NULL) {		if (be != NULL) {
▲ Show 20 Lines • Show All 182 Lines • ▼ Show 20 Lines

int		int
blockif_candelete(struct blockif_ctxt *bc)		blockif_candelete(struct blockif_ctxt *bc)
{		{

assert(bc->bc_magic == BLOCKIF_SIG);		assert(bc->bc_magic == BLOCKIF_SIG);
return (bc->bc_candelete);		return (bc->bc_candelete);
}		}

		void
		blockif_pause(struct blockif_ctxt *bc)
		{
		assert(bc != NULL);
		assert(bc->bc_magic == BLOCKIF_SIG);

		pthread_mutex_lock(&bc->bc_mtx);
		bc->bc_paused = 1;
		/* The interface is paused. Wait for workers to finish their work */
		while (bc->bc_work_count)
		pthread_cond_wait(&bc->bc_work_done_cond, &bc->bc_mtx);
		pthread_mutex_unlock(&bc->bc_mtx);

		if (blockif_flush_bc(bc))
		fprintf(stderr, "%s: [WARN] failed to flush backing file.\r\n",
		__func__);
		}

		void
		blockif_resume(struct blockif_ctxt *bc)
		{
		assert(bc != NULL);
		assert(bc->bc_magic == BLOCKIF_SIG);

		pthread_mutex_lock(&bc->bc_mtx);
		bc->bc_paused = 0;
		/* resume the threads waiting for paused */
		pthread_cond_broadcast(&bc->bc_paused_cond);
		/* kick the threads after restore */
		pthread_cond_broadcast(&bc->bc_cond);
		pthread_mutex_unlock(&bc->bc_mtx);
		}

		int
		blockif_snapshot_req(struct blockif_req br, struct vm_snapshot_meta meta)
		{
		int i;
		struct iovec *iov;
		int ret;

		SNAPSHOT_VAR_OR_LEAVE(br->br_iovcnt, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(br->br_offset, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(br->br_resid, meta, ret, done);

		/* XXX: The callback and parameter must be filled by the virtualized
		* device that uses the interface, during its init; we're not touching
		* them here
		*/

		/* Snapshot the iovecs */
		for (i = 0; i < br->br_iovcnt; i++) {
		iov = &br->br_iov[i];

		SNAPSHOT_VAR_OR_LEAVE(iov->iov_len, meta, ret, done);
		/* we assume the iov is a guest-mapped address */
		SNAPSHOT_GUEST2HOST_ADDR_OR_LEAVE(iov->iov_base, iov->iov_len,
		false, meta, ret, done);
		}

		done:
		return (ret);
		}

		int
		blockif_snapshot(struct blockif_ctxt bc, struct vm_snapshot_meta meta)
		{
		int ret;

		if (bc->bc_paused == 0) {
		fprintf(stderr, "%s: Snapshot failed: "
		"interface not paused.\r\n", __func__);
		return (ENXIO);
		}

		pthread_mutex_lock(&bc->bc_mtx);

		SNAPSHOT_VAR_OR_LEAVE(bc->bc_magic, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_ischr, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_isgeom, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_candelete, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_rdonly, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_size, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_sectsz, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_psectsz, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_psectoff, meta, ret, done);
		SNAPSHOT_VAR_OR_LEAVE(bc->bc_closing, meta, ret, done);
		pmooney_pfmooney.comUnsubmitted Not Done Inline Actions Is there reason to believe that it's not necessary to allow the restoring host to query these parameters itself when bringing up the blockdev there? It could be that aspects of the device (particularly with respect to its capabilities) may change. pmooney_pfmooney.com: Is there reason to believe that it's not necessary to allow the restoring host to query these…
		darius.mihaim_gmail.comUnsubmitted Done Inline Actions If the information can be easily queried, the mechanism can be changed. However, the restore mechanism will likely become more complex, and relying on other saved data, such as guest memory, may not improve security as it is saved in a similar fashion (copied in/from a file on disk). darius.mihaim_gmail.com: If the information can be easily queried, the mechanism can be changed. However, the restore…

		done:
		pthread_mutex_unlock(&bc->bc_mtx);
		return (ret);
		}