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nvme: Add support for Read Data and Write Data in CMBs.
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Add the ability for the NVMe model to support both the RDS and WDS
modes in the Controller Memory Buffer.

Although not currently supported in the upstreamed Linux kernel a fork
with support exists [1] and user-space test programs that build on
this also exist [2].

Useful for testing CMB functionality in preperation for real CMB
enabled NVMe devices (coming soon).

[1] https://github.com/sbates130272/linux-p2pmem
[2] https://github.com/sbates130272/p2pmem-test

Signed-off-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
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@sbates130272 @kevmw
sbates130272 authored and kevmw committed Jun 26, 2017
1 parent ea4f3ce commit b2b2b67
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Showing 2 changed files with 58 additions and 26 deletions.
83 changes: 57 additions & 26 deletions hw/block/nvme.c
View file
Expand Up @@ -21,7 +21,7 @@
* cmb_size_mb=<cmb_size_mb[optional]>
*
* Note cmb_size_mb denotes size of CMB in MB. CMB is assumed to be at
* offset 0 in BAR2 and supports SQS only for now.
* offset 0 in BAR2 and supports only WDS, RDS and SQS for now.
*/

#include "qemu/osdep.h"
Expand Down Expand Up @@ -93,19 +93,24 @@ static void nvme_isr_notify(NvmeCtrl *n, NvmeCQueue *cq)
}
}

static uint16_t nvme_map_prp(QEMUSGList *qsg, uint64_t prp1, uint64_t prp2,
uint32_t len, NvmeCtrl *n)
static uint16_t nvme_map_prp(QEMUSGList *qsg, QEMUIOVector *iov, uint64_t prp1,
uint64_t prp2, uint32_t len, NvmeCtrl *n)
{
hwaddr trans_len = n->page_size - (prp1 % n->page_size);
trans_len = MIN(len, trans_len);
int num_prps = (len >> n->page_bits) + 1;

if (!prp1) {
return NVME_INVALID_FIELD | NVME_DNR;
} else if (n->cmbsz && prp1 >= n->ctrl_mem.addr &&
prp1 < n->ctrl_mem.addr + int128_get64(n->ctrl_mem.size)) {
qsg->nsg = 0;
qemu_iovec_init(iov, num_prps);
qemu_iovec_add(iov, (void *)&n->cmbuf[prp1 - n->ctrl_mem.addr], trans_len);
} else {
pci_dma_sglist_init(qsg, &n->parent_obj, num_prps);
qemu_sglist_add(qsg, prp1, trans_len);
}

pci_dma_sglist_init(qsg, &n->parent_obj, num_prps);
qemu_sglist_add(qsg, prp1, trans_len);
len -= trans_len;
if (len) {
if (!prp2) {
Expand All @@ -118,7 +123,7 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, uint64_t prp1, uint64_t prp2,

nents = (len + n->page_size - 1) >> n->page_bits;
prp_trans = MIN(n->max_prp_ents, nents) * sizeof(uint64_t);
pci_dma_read(&n->parent_obj, prp2, (void *)prp_list, prp_trans);
nvme_addr_read(n, prp2, (void *)prp_list, prp_trans);
while (len != 0) {
uint64_t prp_ent = le64_to_cpu(prp_list[i]);

Expand All @@ -130,7 +135,7 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, uint64_t prp1, uint64_t prp2,
i = 0;
nents = (len + n->page_size - 1) >> n->page_bits;
prp_trans = MIN(n->max_prp_ents, nents) * sizeof(uint64_t);
pci_dma_read(&n->parent_obj, prp_ent, (void *)prp_list,
nvme_addr_read(n, prp_ent, (void *)prp_list,
prp_trans);
prp_ent = le64_to_cpu(prp_list[i]);
}
Expand All @@ -140,15 +145,23 @@ static uint16_t nvme_map_prp(QEMUSGList *qsg, uint64_t prp1, uint64_t prp2,
}

trans_len = MIN(len, n->page_size);
qemu_sglist_add(qsg, prp_ent, trans_len);
if (qsg->nsg){
qemu_sglist_add(qsg, prp_ent, trans_len);
} else {
qemu_iovec_add(iov, (void *)&n->cmbuf[prp_ent - n->ctrl_mem.addr], trans_len);
}
len -= trans_len;
i++;
}
} else {
if (prp2 & (n->page_size - 1)) {
goto unmap;
}
qemu_sglist_add(qsg, prp2, len);
if (qsg->nsg) {
qemu_sglist_add(qsg, prp2, len);
} else {
qemu_iovec_add(iov, (void *)&n->cmbuf[prp2 - n->ctrl_mem.addr], trans_len);
}
}
}
return NVME_SUCCESS;
Expand All @@ -162,16 +175,24 @@ static uint16_t nvme_dma_read_prp(NvmeCtrl *n, uint8_t *ptr, uint32_t len,
uint64_t prp1, uint64_t prp2)
{
QEMUSGList qsg;
QEMUIOVector iov;
uint16_t status = NVME_SUCCESS;

if (nvme_map_prp(&qsg, prp1, prp2, len, n)) {
if (nvme_map_prp(&qsg, &iov, prp1, prp2, len, n)) {
return NVME_INVALID_FIELD | NVME_DNR;
}
if (dma_buf_read(ptr, len, &qsg)) {
if (qsg.nsg > 0) {
if (dma_buf_read(ptr, len, &qsg)) {
status = NVME_INVALID_FIELD | NVME_DNR;
}
qemu_sglist_destroy(&qsg);
return NVME_INVALID_FIELD | NVME_DNR;
} else {
if (qemu_iovec_to_buf(&iov, 0, ptr, len) != len) {
status = NVME_INVALID_FIELD | NVME_DNR;
}
qemu_iovec_destroy(&iov);
}
qemu_sglist_destroy(&qsg);
return NVME_SUCCESS;
return status;
}

static void nvme_post_cqes(void *opaque)
Expand Down Expand Up @@ -285,20 +306,27 @@ static uint16_t nvme_rw(NvmeCtrl *n, NvmeNamespace *ns, NvmeCmd *cmd,
return NVME_LBA_RANGE | NVME_DNR;
}

if (nvme_map_prp(&req->qsg, prp1, prp2, data_size, n)) {
if (nvme_map_prp(&req->qsg, &req->iov, prp1, prp2, data_size, n)) {
block_acct_invalid(blk_get_stats(n->conf.blk), acct);
return NVME_INVALID_FIELD | NVME_DNR;
}

assert((nlb << data_shift) == req->qsg.size);

req->has_sg = true;
dma_acct_start(n->conf.blk, &req->acct, &req->qsg, acct);
req->aiocb = is_write ?
dma_blk_write(n->conf.blk, &req->qsg, data_offset, BDRV_SECTOR_SIZE,
nvme_rw_cb, req) :
dma_blk_read(n->conf.blk, &req->qsg, data_offset, BDRV_SECTOR_SIZE,
nvme_rw_cb, req);
if (req->qsg.nsg > 0) {
req->has_sg = true;
req->aiocb = is_write ?
dma_blk_write(n->conf.blk, &req->qsg, data_offset, BDRV_SECTOR_SIZE,
nvme_rw_cb, req) :
dma_blk_read(n->conf.blk, &req->qsg, data_offset, BDRV_SECTOR_SIZE,
nvme_rw_cb, req);
} else {
req->has_sg = false;
req->aiocb = is_write ?
blk_aio_pwritev(n->conf.blk, data_offset, &req->iov, 0, nvme_rw_cb,
req) :
blk_aio_preadv(n->conf.blk, data_offset, &req->iov, 0, nvme_rw_cb,
req);
}

return NVME_NO_COMPLETE;
}
Expand Down Expand Up @@ -987,11 +1015,14 @@ static int nvme_init(PCIDevice *pci_dev)
NVME_CMBSZ_SET_SQS(n->bar.cmbsz, 1);
NVME_CMBSZ_SET_CQS(n->bar.cmbsz, 0);
NVME_CMBSZ_SET_LISTS(n->bar.cmbsz, 0);
NVME_CMBSZ_SET_RDS(n->bar.cmbsz, 0);
NVME_CMBSZ_SET_WDS(n->bar.cmbsz, 0);
NVME_CMBSZ_SET_RDS(n->bar.cmbsz, 1);
NVME_CMBSZ_SET_WDS(n->bar.cmbsz, 1);
NVME_CMBSZ_SET_SZU(n->bar.cmbsz, 2); /* MBs */
NVME_CMBSZ_SET_SZ(n->bar.cmbsz, n->cmb_size_mb);

n->cmbloc = n->bar.cmbloc;
n->cmbsz = n->bar.cmbsz;

n->cmbuf = g_malloc0(NVME_CMBSZ_GETSIZE(n->bar.cmbsz));
memory_region_init_io(&n->ctrl_mem, OBJECT(n), &nvme_cmb_ops, n,
"nvme-cmb", NVME_CMBSZ_GETSIZE(n->bar.cmbsz));
Expand Down
1 change: 1 addition & 0 deletions hw/block/nvme.h
View file
Expand Up @@ -712,6 +712,7 @@ typedef struct NvmeRequest {
NvmeCqe cqe;
BlockAcctCookie acct;
QEMUSGList qsg;
QEMUIOVector iov;
QTAILQ_ENTRY(NvmeRequest)entry;
} NvmeRequest;

Expand Down

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