From: Philippe Mathieu-Daudé <philmd@redhat.com>

Fix when building with -Wshorten-64-to-32:

warning: implicit conversion loses integer precision: 'unsigned long' to 'int' [-Wshorten-64-to-32]

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-2-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

block/trace-events | 2 +-

1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/trace-events b/block/trace-events

index XXXXXXX..XXXXXXX 100644

--- a/block/trace-events

+++ b/block/trace-events

@@ -XXX,XX +XXX,XX @@ nvme_dsm(void *s, uint64_t offset, uint64_t bytes) "s %p offset 0x%"PRIx64" byte

nvme_dsm_done(void *s, uint64_t offset, uint64_t bytes, int ret) "s %p offset 0x%"PRIx64" bytes %"PRId64" ret %d"

nvme_dma_map_flush(void *s) "s %p"

nvme_free_req_queue_wait(void *s, unsigned q_index) "s %p q #%u"

-nvme_create_queue_pair(unsigned q_index, void *q, unsigned size, void *aio_context, int fd) "index %u q %p size %u aioctx %p fd %d"

+nvme_create_queue_pair(unsigned q_index, void *q, size_t size, void *aio_context, int fd) "index %u q %p size %zu aioctx %p fd %d"

nvme_free_queue_pair(unsigned q_index, void *q) "index %u q %p"

nvme_cmd_map_qiov(void *s, void *cmd, void *req, void *qiov, int entries) "s %p cmd %p req %p qiov %p entries %d"

nvme_cmd_map_qiov_pages(void *s, int i, uint64_t page) "s %p page[%d] 0x%"PRIx64

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Instead of displaying the error on stderr, use error_report()

which also report to the monitor.

Reviewed-by: Fam Zheng <fam@euphon.net>

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-3-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

util/vfio-helpers.c | 4 ++--

1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c

index XXXXXXX..XXXXXXX 100644

--- a/util/vfio-helpers.c

+++ b/util/vfio-helpers.c

@@ -XXX,XX +XXX,XX @@ static bool qemu_vfio_verify_mappings(QEMUVFIOState *s)

if (QEMU_VFIO_DEBUG) {

for (i = 0; i < s->nr_mappings - 1; ++i) {

if (!(s->mappings[i].host < s->mappings[i + 1].host)) {

- fprintf(stderr, "item %d not sorted!\n", i);

+ error_report("item %d not sorted!", i);

qemu_vfio_dump_mappings(s);

return false;

}

if (!(s->mappings[i].host + s->mappings[i].size <=

s->mappings[i + 1].host)) {

- fprintf(stderr, "item %d overlap with next!\n", i);

+ error_report("item %d overlap with next!", i);

qemu_vfio_dump_mappings(s);

return false;

}

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

qemu_vfio_add_mapping() returns a pointer to an indexed entry

in pre-allocated QEMUVFIOState::mappings[], thus can not be NULL.

Remove the pointless check.

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-5-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

util/vfio-helpers.c | 4 ----

1 file changed, 4 deletions(-)

diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c

index XXXXXXX..XXXXXXX 100644

--- a/util/vfio-helpers.c

+++ b/util/vfio-helpers.c

@@ -XXX,XX +XXX,XX @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

}

mapping = qemu_vfio_add_mapping(s, host, size, index + 1, iova0);

- if (!mapping) {

- ret = -ENOMEM;

- goto out;

- }

assert(qemu_vfio_verify_mappings(s));

ret = qemu_vfio_do_mapping(s, host, size, iova0);

if (ret) {

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

nvme_create_queue_pair() does not return a boolean value (indicating

eventual error) but a pointer, and is inconsistent in how it fills the

error handler. To fulfill callers expectations, always set an error

message on failure.

Reported-by: Auger Eric <eric.auger@redhat.com>

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-6-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

block/nvme.c | 3 +++

1 file changed, 3 insertions(+)

diff --git a/block/nvme.c b/block/nvme.c

index XXXXXXX..XXXXXXX 100644

--- a/block/nvme.c

+++ b/block/nvme.c

@@ -XXX,XX +XXX,XX @@ static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,

q = g_try_new0(NVMeQueuePair, 1);

if (!q) {

+ error_setg(errp, "Cannot allocate queue pair");

return NULL;

}

trace_nvme_create_queue_pair(idx, q, size, aio_context,

@@ -XXX,XX +XXX,XX @@ static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,

qemu_real_host_page_size);

q->prp_list_pages = qemu_try_memalign(qemu_real_host_page_size, bytes);

if (!q->prp_list_pages) {

+ error_setg(errp, "Cannot allocate PRP page list");

goto fail;

}

memset(q->prp_list_pages, 0, bytes);

@@ -XXX,XX +XXX,XX @@ static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,

r = qemu_vfio_dma_map(s->vfio, q->prp_list_pages, bytes,

false, &prp_list_iova);

if (r) {

+ error_setg_errno(errp, -r, "Cannot map buffer for DMA");

goto fail;

}

q->free_req_head = -1;

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Currently qemu_vfio_dma_map() displays errors on stderr.

When using management interface, this information is simply

lost. Pass qemu_vfio_dma_map() an Error** handle so it can

propagate the error to callers.

Reviewed-by: Fam Zheng <fam@euphon.net>

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-7-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

include/qemu/vfio-helpers.h | 2 +-

block/nvme.c | 22 +++++++++++-----------

util/vfio-helpers.c | 10 ++++++----

3 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/include/qemu/vfio-helpers.h b/include/qemu/vfio-helpers.h

index XXXXXXX..XXXXXXX 100644

--- a/include/qemu/vfio-helpers.h

+++ b/include/qemu/vfio-helpers.h

@@ -XXX,XX +XXX,XX @@ typedef struct QEMUVFIOState QEMUVFIOState;

QEMUVFIOState *qemu_vfio_open_pci(const char *device, Error **errp);

void qemu_vfio_close(QEMUVFIOState *s);

int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

- bool temporary, uint64_t *iova_list);

+ bool temporary, uint64_t *iova_list, Error **errp);

int qemu_vfio_dma_reset_temporary(QEMUVFIOState *s);

void qemu_vfio_dma_unmap(QEMUVFIOState *s, void *host);

void *qemu_vfio_pci_map_bar(QEMUVFIOState *s, int index,

diff --git a/block/nvme.c b/block/nvme.c

index XXXXXXX..XXXXXXX 100644

--- a/block/nvme.c

+++ b/block/nvme.c

@@ -XXX,XX +XXX,XX @@ static bool nvme_init_queue(BDRVNVMeState *s, NVMeQueue *q,

return false;

}

memset(q->queue, 0, bytes);

- r = qemu_vfio_dma_map(s->vfio, q->queue, bytes, false, &q->iova);

+ r = qemu_vfio_dma_map(s->vfio, q->queue, bytes, false, &q->iova, errp);

if (r) {

- error_setg(errp, "Cannot map queue");

- return false;

+ error_prepend(errp, "Cannot map queue: ");

}

- return true;

+ return r == 0;

}

static void nvme_free_queue_pair(NVMeQueuePair *q)

@@ -XXX,XX +XXX,XX @@ static NVMeQueuePair *nvme_create_queue_pair(BDRVNVMeState *s,

qemu_co_queue_init(&q->free_req_queue);

q->completion_bh = aio_bh_new(aio_context, nvme_process_completion_bh, q);

r = qemu_vfio_dma_map(s->vfio, q->prp_list_pages, bytes,

- false, &prp_list_iova);

+ false, &prp_list_iova, errp);

if (r) {

- error_setg_errno(errp, -r, "Cannot map buffer for DMA");

+ error_prepend(errp, "Cannot map buffer for DMA: ");

goto fail;

}

q->free_req_head = -1;

@@ -XXX,XX +XXX,XX @@ static bool nvme_identify(BlockDriverState *bs, int namespace, Error **errp)

error_setg(errp, "Cannot allocate buffer for identify response");

goto out;

}

- r = qemu_vfio_dma_map(s->vfio, id, id_size, true, &iova);

+ r = qemu_vfio_dma_map(s->vfio, id, id_size, true, &iova, errp);

if (r) {

- error_setg(errp, "Cannot map buffer for DMA");

+ error_prepend(errp, "Cannot map buffer for DMA: ");

goto out;

}

@@ -XXX,XX +XXX,XX @@ static coroutine_fn int nvme_cmd_map_qiov(BlockDriverState *bs, NvmeCmd *cmd,

try_map:

r = qemu_vfio_dma_map(s->vfio,

qiov->iov[i].iov_base,

- len, true, &iova);

+ len, true, &iova, NULL);

if (r == -ENOSPC) {

/*

* In addition to the -ENOMEM error, the VFIO_IOMMU_MAP_DMA

@@ -XXX,XX +XXX,XX @@ static void nvme_aio_unplug(BlockDriverState *bs)

static void nvme_register_buf(BlockDriverState *bs, void *host, size_t size)

{

int ret;

+ Error *local_err = NULL;

BDRVNVMeState *s = bs->opaque;

- ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL);

+ ret = qemu_vfio_dma_map(s->vfio, host, size, false, NULL, &local_err);

if (ret) {

/* FIXME: we may run out of IOVA addresses after repeated

* bdrv_register_buf/bdrv_unregister_buf, because nvme_vfio_dma_unmap

* doesn't reclaim addresses for fixed mappings. */

- error_report("nvme_register_buf failed: %s", strerror(-ret));

+ error_reportf_err(local_err, "nvme_register_buf failed: ");

}

}

diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c

index XXXXXXX..XXXXXXX 100644

--- a/util/vfio-helpers.c

+++ b/util/vfio-helpers.c

@@ -XXX,XX +XXX,XX @@ static void qemu_vfio_ram_block_added(RAMBlockNotifier *n, void *host,

size_t size, size_t max_size)

{

QEMUVFIOState *s = container_of(n, QEMUVFIOState, ram_notifier);

+ Error *local_err = NULL;

int ret;

trace_qemu_vfio_ram_block_added(s, host, max_size);

- ret = qemu_vfio_dma_map(s, host, max_size, false, NULL);

+ ret = qemu_vfio_dma_map(s, host, max_size, false, NULL, &local_err);

if (ret) {

- error_report("qemu_vfio_dma_map(%p, %zu) failed: %s", host, max_size,

- strerror(-ret));

+ error_reportf_err(local_err,

+ "qemu_vfio_dma_map(%p, %zu) failed: ",

+ host, max_size);

}

}

@@ -XXX,XX +XXX,XX @@ qemu_vfio_find_temp_iova(QEMUVFIOState *s, size_t size, uint64_t *iova)

* mapping status within this area is not allowed).

*/

int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

- bool temporary, uint64_t *iova)

+ bool temporary, uint64_t *iova, Error **errp)

{

int ret = 0;

int index;

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Extract qemu_vfio_water_mark_reached() for readability,

and have it provide an error hint it its Error* handle.

Suggested-by: Klaus Jensen <k.jensen@samsung.com>

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-8-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

util/vfio-helpers.c | 17 ++++++++++++++++-

1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c

index XXXXXXX..XXXXXXX 100644

--- a/util/vfio-helpers.c

+++ b/util/vfio-helpers.c

@@ -XXX,XX +XXX,XX @@ qemu_vfio_find_temp_iova(QEMUVFIOState *s, size_t size, uint64_t *iova)

return -ENOMEM;

}

+/**

+ * qemu_vfio_water_mark_reached:

+ *

+ * Returns %true if high watermark has been reached, %false otherwise.

+ */

+static bool qemu_vfio_water_mark_reached(QEMUVFIOState *s, size_t size,

+ Error **errp)

+{

+ if (s->high_water_mark - s->low_water_mark + 1 < size) {

+ error_setg(errp, "iova exhausted (water mark reached)");

+ return true;

+ }

+ return false;

+}

+

/* Map [host, host + size) area into a contiguous IOVA address space, and store

* the result in @iova if not NULL. The caller need to make sure the area is

* aligned to page size, and mustn't overlap with existing mapping areas (split

@@ -XXX,XX +XXX,XX @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

if (mapping) {

iova0 = mapping->iova + ((uint8_t *)host - (uint8_t *)mapping->host);

} else {

- if (s->high_water_mark - s->low_water_mark + 1 < size) {

+ if (qemu_vfio_water_mark_reached(s, size, errp)) {

ret = -ENOMEM;

goto out;

}

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Both qemu_vfio_find_fixed_iova() and qemu_vfio_find_temp_iova()

return an errno which is unused (or overwritten). Have them propagate

eventual errors to callers, returning a boolean (which is what the

Error API recommends, see commit e3fe3988d78 "error: Document Error

API usage rules" for rationale).

Suggested-by: Klaus Jensen <k.jensen@samsung.com>

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-9-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

util/vfio-helpers.c | 24 ++++++++++++++----------

1 file changed, 14 insertions(+), 10 deletions(-)

diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c

index XXXXXXX..XXXXXXX 100644

--- a/util/vfio-helpers.c

+++ b/util/vfio-helpers.c

@@ -XXX,XX +XXX,XX @@ static bool qemu_vfio_verify_mappings(QEMUVFIOState *s)

return true;

}

-static int

-qemu_vfio_find_fixed_iova(QEMUVFIOState *s, size_t size, uint64_t *iova)

+static bool qemu_vfio_find_fixed_iova(QEMUVFIOState *s, size_t size,

+ uint64_t *iova, Error **errp)

{

int i;

@@ -XXX,XX +XXX,XX @@ qemu_vfio_find_fixed_iova(QEMUVFIOState *s, size_t size, uint64_t *iova)

s->usable_iova_ranges[i].end - s->low_water_mark + 1 == 0) {

*iova = s->low_water_mark;

s->low_water_mark += size;

- return 0;

+ return true;

}

}

- return -ENOMEM;

+ error_setg(errp, "fixed iova range not found");

+

+ return false;

}

-static int

-qemu_vfio_find_temp_iova(QEMUVFIOState *s, size_t size, uint64_t *iova)

+static bool qemu_vfio_find_temp_iova(QEMUVFIOState *s, size_t size,

+ uint64_t *iova, Error **errp)

{

int i;

@@ -XXX,XX +XXX,XX @@ qemu_vfio_find_temp_iova(QEMUVFIOState *s, size_t size, uint64_t *iova)

s->high_water_mark - s->usable_iova_ranges[i].start + 1 == 0) {

*iova = s->high_water_mark - size;

s->high_water_mark = *iova;

- return 0;

+ return true;

}

}

- return -ENOMEM;

+ error_setg(errp, "temporary iova range not found");

+

+ return false;

}

/**

@@ -XXX,XX +XXX,XX @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

goto out;

}

if (!temporary) {

- if (qemu_vfio_find_fixed_iova(s, size, &iova0)) {

+ if (!qemu_vfio_find_fixed_iova(s, size, &iova0, errp)) {

ret = -ENOMEM;

goto out;

}

@@ -XXX,XX +XXX,XX @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

}

qemu_vfio_dump_mappings(s);

} else {

- if (qemu_vfio_find_temp_iova(s, size, &iova0)) {

+ if (!qemu_vfio_find_temp_iova(s, size, &iova0, errp)) {

ret = -ENOMEM;

goto out;

}

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

To simplify qemu_vfio_dma_map():

- reduce 'ret' (returned value) scope by returning errno directly,

- remove the goto 'out' label.

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-10-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

util/vfio-helpers.c | 23 ++++++++++-------------

1 file changed, 10 insertions(+), 13 deletions(-)

diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c

index XXXXXXX..XXXXXXX 100644

--- a/util/vfio-helpers.c

+++ b/util/vfio-helpers.c

@@ -XXX,XX +XXX,XX @@ static bool qemu_vfio_water_mark_reached(QEMUVFIOState *s, size_t size,

int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

bool temporary, uint64_t *iova, Error **errp)

{

- int ret = 0;

int index;

IOVAMapping *mapping;

uint64_t iova0;

@@ -XXX,XX +XXX,XX @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

if (mapping) {

iova0 = mapping->iova + ((uint8_t *)host - (uint8_t *)mapping->host);

} else {

+ int ret;

+

if (qemu_vfio_water_mark_reached(s, size, errp)) {

- ret = -ENOMEM;

- goto out;

+ return -ENOMEM;

}

if (!temporary) {

if (!qemu_vfio_find_fixed_iova(s, size, &iova0, errp)) {

- ret = -ENOMEM;

- goto out;

+ return -ENOMEM;

}

mapping = qemu_vfio_add_mapping(s, host, size, index + 1, iova0);

assert(qemu_vfio_verify_mappings(s));

ret = qemu_vfio_do_mapping(s, host, size, iova0);

- if (ret) {

+ if (ret < 0) {

qemu_vfio_undo_mapping(s, mapping, NULL);

- goto out;

+ return ret;

}

qemu_vfio_dump_mappings(s);

} else {

if (!qemu_vfio_find_temp_iova(s, size, &iova0, errp)) {

- ret = -ENOMEM;

- goto out;

+ return -ENOMEM;

}

ret = qemu_vfio_do_mapping(s, host, size, iova0);

- if (ret) {

- goto out;

+ if (ret < 0) {

+ return ret;

}

}

}

@@ -XXX,XX +XXX,XX @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

if (iova) {

*iova = iova0;

}

-out:

- return ret;

+ return 0;

}

/* Reset the high watermark and free all "temporary" mappings. */

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

Pass qemu_vfio_do_mapping() an Error* argument so it can propagate

any error to callers. Replace error_report() which only report

to the monitor by the more generic error_setg_errno().

Reviewed-by: Fam Zheng <fam@euphon.net>

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-11-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

util/vfio-helpers.c | 8 ++++----

1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/util/vfio-helpers.c b/util/vfio-helpers.c

index XXXXXXX..XXXXXXX 100644

--- a/util/vfio-helpers.c

+++ b/util/vfio-helpers.c

@@ -XXX,XX +XXX,XX @@ static IOVAMapping *qemu_vfio_add_mapping(QEMUVFIOState *s,

/* Do the DMA mapping with VFIO. */

static int qemu_vfio_do_mapping(QEMUVFIOState *s, void *host, size_t size,

- uint64_t iova)

+ uint64_t iova, Error **errp)

{

struct vfio_iommu_type1_dma_map dma_map = {

.argsz = sizeof(dma_map),

@@ -XXX,XX +XXX,XX @@ static int qemu_vfio_do_mapping(QEMUVFIOState *s, void *host, size_t size,

trace_qemu_vfio_do_mapping(s, host, iova, size);

if (ioctl(s->container, VFIO_IOMMU_MAP_DMA, &dma_map)) {

- error_report("VFIO_MAP_DMA failed: %s", strerror(errno));

+ error_setg_errno(errp, errno, "VFIO_MAP_DMA failed");

return -errno;

}

return 0;

@@ -XXX,XX +XXX,XX @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

mapping = qemu_vfio_add_mapping(s, host, size, index + 1, iova0);

assert(qemu_vfio_verify_mappings(s));

- ret = qemu_vfio_do_mapping(s, host, size, iova0);

+ ret = qemu_vfio_do_mapping(s, host, size, iova0, errp);

if (ret < 0) {

qemu_vfio_undo_mapping(s, mapping, NULL);

return ret;

@@ -XXX,XX +XXX,XX @@ int qemu_vfio_dma_map(QEMUVFIOState *s, void *host, size_t size,

if (!qemu_vfio_find_temp_iova(s, size, &iova0, errp)) {

return -ENOMEM;

}

- ret = qemu_vfio_do_mapping(s, host, size, iova0);

+ ret = qemu_vfio_do_mapping(s, host, size, iova0, errp);

if (ret < 0) {

return ret;

}

--

2.31.1

From: Philippe Mathieu-Daudé <philmd@redhat.com>

We expect the first qemu_vfio_dma_map() to fail (indicating

DMA mappings exhaustion, see commit 15a730e7a3a). Do not

report the first failure as error, since we are going to

flush the mappings and retry.

This removes spurious error message displayed on the monitor:

(qemu) c

(qemu) qemu-kvm: VFIO_MAP_DMA failed: No space left on device

(qemu) info status

VM status: running

Reported-by: Tingting Mao <timao@redhat.com>

Reviewed-by: Klaus Jensen <k.jensen@samsung.com>

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Message-id: 20210902070025.197072-12-philmd@redhat.com

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

---

block/nvme.c | 8 +++++++-

1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/block/nvme.c b/block/nvme.c

index XXXXXXX..XXXXXXX 100644

--- a/block/nvme.c

+++ b/block/nvme.c

@@ -XXX,XX +XXX,XX @@ static coroutine_fn int nvme_cmd_map_qiov(BlockDriverState *bs, NvmeCmd *cmd,

uint64_t *pagelist = req->prp_list_page;

int i, j, r;

int entries = 0;

+ Error *local_err = NULL, **errp = NULL;

assert(qiov->size);

assert(QEMU_IS_ALIGNED(qiov->size, s->page_size));

@@ -XXX,XX +XXX,XX @@ static coroutine_fn int nvme_cmd_map_qiov(BlockDriverState *bs, NvmeCmd *cmd,

try_map:

r = qemu_vfio_dma_map(s->vfio,

qiov->iov[i].iov_base,

- len, true, &iova, NULL);

+ len, true, &iova, errp);

if (r == -ENOSPC) {

/*

* In addition to the -ENOMEM error, the VFIO_IOMMU_MAP_DMA

@@ -XXX,XX +XXX,XX @@ try_map:

goto fail;

}

}

+ errp = &local_err;

+

goto try_map;

}

if (r) {

@@ -XXX,XX +XXX,XX @@ fail:

* because they are already mapped before calling this function; for

* temporary mappings, a later nvme_cmd_(un)map_qiov will reclaim by

* calling qemu_vfio_dma_reset_temporary when necessary. */

+ if (local_err) {

+ error_reportf_err(local_err, "Cannot map buffer for DMA: ");

+ }

return r;

}

--

2.31.1