nvme: implement the Flush command

Implement a real flush instead of faking it.  This is especially important
as Qemu assume Write back cashing by default and thus requires a working
cache flush operation for data integrity.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Christoph Hellwig 2015-06-11 12:01:38 +02:00 committed by Kevin Wolf
parent f3a1b5068c
commit 8b9d74e0ee
2 changed files with 17 additions and 3 deletions

View File

@ -207,11 +207,23 @@ static void nvme_rw_cb(void *opaque, int ret)
} else {
req->status = NVME_INTERNAL_DEV_ERROR;
}
qemu_sglist_destroy(&req->qsg);
if (req->has_sg) {
qemu_sglist_destroy(&req->qsg);
}
nvme_enqueue_req_completion(cq, req);
}
static uint16_t nvme_flush(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
NvmeRequest *req)
{
req->has_sg = false;
block_acct_start(blk_get_stats(n->conf.blk), &req->acct, 0,
BLOCK_ACCT_FLUSH);
req->aiocb = blk_aio_flush(n->conf.blk, nvme_rw_cb, req);
return NVME_NO_COMPLETE;
}
static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
NvmeRequest *req)
{
@ -235,6 +247,7 @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
}
assert((nlb << data_shift) == req->qsg.size);
req->has_sg = true;
dma_acct_start(n->conf.blk, &req->acct, &req->qsg,
is_write ? BLOCK_ACCT_WRITE : BLOCK_ACCT_READ);
req->aiocb = is_write ?
@ -256,7 +269,7 @@ static uint16_t nvme_io_cmd(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
ns = &n->namespaces[nsid - 1];
switch (cmd->opcode) {
case NVME_CMD_FLUSH:
return NVME_SUCCESS;
return nvme_flush(n, ns, cmd, req);
case NVME_CMD_WRITE:
case NVME_CMD_READ:
return nvme_rw(n, ns, cmd, req);

View File

@ -638,6 +638,7 @@ typedef struct NvmeRequest {
struct NvmeSQueue *sq;
BlockAIOCB *aiocb;
uint16_t status;
bool has_sg;
NvmeCqe cqe;
BlockAcctCookie acct;
QEMUSGList qsg;