Commit 8b9d74e0 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Kevin Wolf
Browse files

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: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarKeith Busch <keith.busch@intel.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent f3a1b506

hw/block/nvme.c

+16 −3
Original line number Diff line number Diff line
@@ -207,11 +207,23 @@ static void nvme_rw_cb(void *opaque, int ret) 
    } else {

        req->status = NVME_INTERNAL_DEV_ERROR;

    }



    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);

hw/block/nvme.h

+1 −0
Original line number Diff line number Diff line
@@ -638,6 +638,7 @@ typedef struct NvmeRequest { 
    struct NvmeSQueue       *sq;

    BlockAIOCB              *aiocb;

    uint16_t                status;

    bool                    has_sg;

    NvmeCqe                 cqe;

    BlockAcctCookie         acct;

    QEMUSGList              qsg;