[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v3 08/16] block/nvme: Use union of NvmeIdCtrl / NvmeIdNs structur
From: |
Philippe Mathieu-Daudé |
Subject: |
[PATCH v3 08/16] block/nvme: Use union of NvmeIdCtrl / NvmeIdNs structures |
Date: |
Sat, 4 Jul 2020 23:30:43 +0200 |
We allocate an unique chunk of memory then use it for two
different structures. By using an union, we make it clear
the data is overlapping (and we can remove the casts).
Suggested-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
block/nvme.c | 31 +++++++++++++++----------------
1 file changed, 15 insertions(+), 16 deletions(-)
diff --git a/block/nvme.c b/block/nvme.c
index 0e4e5ff107..a611fdd71e 100644
--- a/block/nvme.c
+++ b/block/nvme.c
@@ -508,9 +508,10 @@ static int nvme_cmd_sync(BlockDriverState *bs,
NVMeQueuePair *q,
static void nvme_identify(BlockDriverState *bs, int namespace, Error **errp)
{
BDRVNVMeState *s = bs->opaque;
- NvmeIdCtrl *idctrl;
- NvmeIdNs *idns;
- uint8_t *id;
+ union {
+ NvmeIdCtrl ctrl;
+ NvmeIdNs ns;
+ } *id;
NvmeLBAF *lbaf;
uint16_t oncs;
int r;
@@ -520,14 +521,12 @@ static void nvme_identify(BlockDriverState *bs, int
namespace, Error **errp)
.cdw10 = cpu_to_le32(0x1),
};
- id = qemu_try_blockalign0(bs, sizeof(NvmeIdCtrl));
+ id = qemu_try_blockalign0(bs, sizeof(*id));
if (!id) {
error_setg(errp, "Cannot allocate buffer for identify response");
goto out;
}
- idctrl = (NvmeIdCtrl *)id;
- idns = (NvmeIdNs *)id;
- r = qemu_vfio_dma_map(s->vfio, id, sizeof(NvmeIdCtrl), true, &iova);
+ r = qemu_vfio_dma_map(s->vfio, id, sizeof(*id), true, &iova);
if (r) {
error_setg(errp, "Cannot map buffer for DMA");
goto out;
@@ -539,22 +538,22 @@ static void nvme_identify(BlockDriverState *bs, int
namespace, Error **errp)
goto out;
}
- if (le32_to_cpu(idctrl->nn) < namespace) {
+ if (le32_to_cpu(id->ctrl.nn) < namespace) {
error_setg(errp, "Invalid namespace");
goto out;
}
- s->write_cache_supported = le32_to_cpu(idctrl->vwc) & 0x1;
- s->max_transfer = (idctrl->mdts ? 1 << idctrl->mdts : 0) * s->page_size;
+ s->write_cache_supported = le32_to_cpu(id->ctrl.vwc) & 0x1;
+ s->max_transfer = (id->ctrl.mdts ? 1 << id->ctrl.mdts : 0) * s->page_size;
/* For now the page list buffer per command is one page, to hold at most
* s->page_size / sizeof(uint64_t) entries. */
s->max_transfer = MIN_NON_ZERO(s->max_transfer,
s->page_size / sizeof(uint64_t) * s->page_size);
- oncs = le16_to_cpu(idctrl->oncs);
+ oncs = le16_to_cpu(id->ctrl.oncs);
s->supports_write_zeroes = !!(oncs & NVME_ONCS_WRITE_ZEROS);
s->supports_discard = !!(oncs & NVME_ONCS_DSM);
- memset(id, 0, 4096);
+ memset(id, 0, sizeof(*id));
cmd.cdw10 = 0;
cmd.nsid = cpu_to_le32(namespace);
if (nvme_cmd_sync(bs, s->queues[QUEUE_INDEX_ADMIN], &cmd)) {
@@ -562,11 +561,11 @@ static void nvme_identify(BlockDriverState *bs, int
namespace, Error **errp)
goto out;
}
- s->nsze = le64_to_cpu(idns->nsze);
- lbaf = &idns->lbaf[NVME_ID_NS_FLBAS_INDEX(idns->flbas)];
+ s->nsze = le64_to_cpu(id->ns.nsze);
+ lbaf = &id->ns.lbaf[NVME_ID_NS_FLBAS_INDEX(id->ns.flbas)];
- if (NVME_ID_NS_DLFEAT_WRITE_ZEROES(idns->dlfeat) &&
- NVME_ID_NS_DLFEAT_READ_BEHAVIOR(idns->dlfeat) ==
+ if (NVME_ID_NS_DLFEAT_WRITE_ZEROES(id->ns.dlfeat) &&
+ NVME_ID_NS_DLFEAT_READ_BEHAVIOR(id->ns.dlfeat) ==
NVME_ID_NS_DLFEAT_READ_BEHAVIOR_ZEROES) {
bs->supported_write_flags |= BDRV_REQ_MAY_UNMAP;
}
--
2.21.3
- [PATCH v3 00/16] block/nvme: Various cleanups required to use multiple queues, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 01/16] block/nvme: Replace magic value by SCALE_MS definition, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 02/16] block/nvme: Avoid further processing if trace event not enabled, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 03/16] block/nvme: Let nvme_create_queue_pair() fail gracefully, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 04/16] block/nvme: Define QUEUE_INDEX macros to ease code review, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 05/16] block/nvme: Improve error message when IO queue creation failed, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 06/16] block/nvme: Use common error path in nvme_add_io_queue(), Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 07/16] block/nvme: Rename local variable, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 08/16] block/nvme: Use union of NvmeIdCtrl / NvmeIdNs structures,
Philippe Mathieu-Daudé <=
- [PATCH v3 09/16] block/nvme: Replace qemu_try_blockalign0 by qemu_try_blockalign/memset, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 10/16] block/nvme: Replace qemu_try_blockalign(bs) by qemu_try_memalign(pg_sz), Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 11/16] block/nvme: Simplify nvme_init_queue() arguments, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 12/16] block/nvme: Replace BDRV_POLL_WHILE by AIO_WAIT_WHILE, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 13/16] block/nvme: Simplify nvme_create_queue_pair() arguments, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 14/16] block/nvme: Extract nvme_poll_queue(), Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 15/16] block/nvme: Move nvme_poll_cb() earlier, Philippe Mathieu-Daudé, 2020/07/04
- [PATCH v3 16/16] block/nvme: Use per-queuepair IRQ notifier and AIO context, Philippe Mathieu-Daudé, 2020/07/04