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Re: [RFC 5/7] hw/cxl/cxl-mailbox-utils: Add mailbox commands to support
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From: |
Jonathan Cameron |
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Subject: |
Re: [RFC 5/7] hw/cxl/cxl-mailbox-utils: Add mailbox commands to support add/release dynamic capacity response |
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Date: |
Mon, 15 May 2023 15:37:55 +0100 |
On Thu, 11 May 2023 17:56:40 +0000
Fan Ni <fan.ni@samsung.com> wrote:
> From: Fan Ni <nifan@outlook.com>
>
> Per CXL spec 3.0, we implemented the two mailbox commands:
> Add Dynamic Capacity Response (Opcode 4802h) 8.2.9.8.9.3, and
> Release Dynamic Capacity Response (Opcode 4803h) 8.2.9.8.9.4.
>
> Signed-off-by: Fan Ni <fan.ni@samsung.com>
> ---
> hw/cxl/cxl-mailbox-utils.c | 223 ++++++++++++++++++++++++++++++++++++
> include/hw/cxl/cxl_device.h | 3 +-
> 2 files changed, 225 insertions(+), 1 deletion(-)
>
> diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
> index ed2ac154cb..7212934627 100644
> --- a/hw/cxl/cxl-mailbox-utils.c
> +++ b/hw/cxl/cxl-mailbox-utils.c
> @@ -84,6 +84,8 @@ enum {
> DCD_CONFIG = 0x48, /*8.2.9.8.9*/
> #define GET_DC_REGION_CONFIG 0x0
> #define GET_DYN_CAP_EXT_LIST 0x1
> + #define ADD_DYN_CAP_RSP 0x2
> + #define RELEASE_DYN_CAP 0x3
> PHYSICAL_SWITCH = 0x51
> #define IDENTIFY_SWITCH_DEVICE 0x0
> };
> @@ -1069,6 +1071,221 @@ static CXLRetCode cmd_dcd_get_dyn_cap_ext_list(struct
> cxl_cmd *cmd,
> return CXL_MBOX_SUCCESS;
> }
>
> +static inline int test_bits(const unsigned long *addr, int nr, int size)
Not obvious what this does from the name. Please add some docs.
> +{
> + unsigned long res = find_next_zero_bit(addr, size + nr, nr);
> +
> + if (res >= nr + size)
> + return 1;
> + else
> + return 0;
> +}
> +
> +static uint8_t find_region_id(struct CXLType3Dev *dev, uint64_t dpa
Operates only on things in dev->dc, so perhaps pass that instead.
> + , uint64_t len)
comma on previous line.
> +{
> + int8_t i = dev->dc.num_regions-1;
> +
> + while (i > 0 && dpa < dev->dc.regions[i].base)
> + i--;
> +
> + if (dpa < dev->dc.regions[i].base
> + || dpa + len > dev->dc.regions[i].base +
> dev->dc.regions[i].len)
> + return dev->dc.num_regions;
> +
> + return i;
> +}
> +
> +static CXLRetCode detect_malformed_extent_list(CXLType3Dev *dev, void *data)
> +{
> + struct updated_dc_extent_list_in_pl {
This is same as used in next function. Pull it out of the functions and
use that type rather than mapping via a void *data pointer.
> + uint32_t num_entries_updated;
> + uint8_t rsvd[4];
> + struct {
> + uint64_t start_dpa;
> + uint64_t len;
> + uint8_t rsvd[8];
> + } QEMU_PACKED updated_entries[];
> + } QEMU_PACKED;
> +
> + struct updated_dc_extent_list_in_pl *in = data;
> + unsigned long *blk_bitmap;
> + uint64_t min_block_size = dev->dc.regions[0].block_size;
> + struct CXLDCD_Region *region = &dev->dc.regions[0];
> + uint32_t i;
> + uint64_t dpa, len;
> + uint8_t rid;
> +
> + for (i = 1; i < dev->dc.num_regions; i++) {
> + region = &dev->dc.regions[i];
> + if (min_block_size > region->block_size)
> + min_block_size = region->block_size;
> + }
> + blk_bitmap = bitmap_new((region->len + region->base
> + - dev->dc.regions[0].base) / min_block_size);
> + g_assert(blk_bitmap);
Abort in bitmap_new() anyway so no need for this. Most qemu allocations
don't need to be checked as they fail hard anyway so we never get to the checks.
> + bitmap_zero(blk_bitmap, (region->len + region->base
> + - dev->dc.regions[0].base) / min_block_size);
bitmap_new() seems to use a g_malloc0 internally so no need to zero again here
I think.
> +
> + for (i = 0; i < in->num_entries_updated; i++) {
> + dpa = in->updated_entries[i].start_dpa;
> + len = in->updated_entries[i].len;
> +
> + rid = find_region_id(dev, dpa, len);
> + if (rid == dev->dc.num_regions) {
Use a goto and single cleanup path having set ret or similar to
the particular issue.
> + g_free(blk_bitmap);
> + return CXL_MBOX_INVALID_PA;
> + }
> + region = &dev->dc.regions[rid];
> + if (dpa % region->block_size || len % region->block_size) {
> + g_free(blk_bitmap);
> + return CXL_MBOX_INVALID_EXTENT_LIST;
goto from here as well.. etc.
> + }
> + /* the dpa range already covered by some other extents in the
> list */
> + if (test_bits(blk_bitmap, dpa/min_block_size,
> len/min_block_size)) {
> + g_free(blk_bitmap);
> + return CXL_MBOX_INVALID_EXTENT_LIST;
> + }
> + bitmap_set(blk_bitmap, dpa/min_block_size, len/min_block_size);
> + }
> +
> + g_free(blk_bitmap);
> + return CXL_MBOX_SUCCESS;
> +}
> +
> +/*
> + * cxl spec 3.0: 8.2.9.8.9.3
> + * Add Dynamic Capacity Response (opcode 4802h)
> + * Assuming extent list is updated when a extent is added, when receiving
> + * the response, verify and ensure the extent is utilized by the host, and
> + * update extent list as needed.
Double space in middle of sentence
> + **/
> +static CXLRetCode cmd_dcd_add_dyn_cap_rsp(struct cxl_cmd *cmd,
> + CXLDeviceState *cxl_dstate,
> + uint16_t *len_unused)
> +{
> + struct add_dyn_cap_ext_list_in_pl {
> + uint32_t num_entries_updated;
> + uint8_t rsvd[4];
> + struct {
> + uint64_t start_dpa;
> + uint64_t len;
> + uint8_t rsvd[8];
> + } QEMU_PACKED updated_entries[];
These extent list entries keep turning up in the code. Pull that out of here
to be a general 'Extent list element' or similar.
> + } QEMU_PACKED;
> +
> + struct add_dyn_cap_ext_list_in_pl *in = (void *)cmd->payload;
> + struct CXLType3Dev *ct3d = container_of(cxl_dstate, CXLType3Dev,
> cxl_dstate);
> + CXLDCDExtentList *extent_list = &ct3d->dc.extents;
> + CXLDCD_Extent *ent;
> + uint32_t i;
> + uint64_t dpa, len;
> + CXLRetCode rs;
> +
> + if (in->num_entries_updated == 0)
> + return CXL_MBOX_SUCCESS;
> +
> + rs = detect_malformed_extent_list(ct3d, in);
> + if (rs != CXL_MBOX_SUCCESS)
> + return rs;
> +
> + for (i = 0; i < in->num_entries_updated; i++) {
> + dpa = in->updated_entries[i].start_dpa;
> + len = in->updated_entries[i].len;
> +
> + /* Todo: check following
> + * One or more of the updated extent lists contain Starting DPA
> + * or Lengths that are out of range of a current extent list
> + * maintained by the device.
> + **/
> +
> + QTAILQ_FOREACH(ent, extent_list, node) {
Add some comments here. Is this a repeated entry test?
> + if (ent->start_dpa == dpa && ent->len == len)
> + return CXL_MBOX_INVALID_PA;
> + if (ent->start_dpa <= dpa
> + && dpa + len <= ent->start_dpa + ent->len) {
Comment needed on this one. Why is it shrinking an existing entry?
> + ent->start_dpa = dpa;
> + ent->len = len;
> + break;
If you break here I think it will only result in return CXL_MBOX_SUCCESS so
might as well do that here.
> + } else if ((dpa < ent->start_dpa + ent->len
> + && dpa + len > ent->start_dpa + ent->len)
Above is new entry would contain existing one.
> + || (dpa < ent->start_dpa && dpa + len >
> ent->start_dpa))
> + return CXL_MBOX_INVALID_EXTENT_LIST;
> + }
> + // a new extent added
Why? This function generally need more documentation.
> + if (!ent) {
> + ent = g_new0(CXLDCD_Extent, 1);
> + assert(ent);
No need. g_new0 will already have blown up before you get here.
> + ent->start_dpa = dpa;
> + ent->len = len;
> + memset(ent->tag, 0, 0x10);
Allocated empty just above, still empty so no need to set it again.
> + ent->shared_seq = 0;
> + QTAILQ_INSERT_TAIL(extent_list, ent, node);
> + }
> + }
> +
> + return CXL_MBOX_SUCCESS;
> +}
> +
> +/*
> + * Spec 3.0: 8.2.9.8.9.4
> + * Release Dynamic Capacity (opcode 4803h)
> + **/
> +static CXLRetCode cmd_dcd_release_dcd_capacity(struct cxl_cmd *cmd,
> + CXLDeviceState *cxl_dstate,
> + uint16_t *len_unused)
> +{
> + struct release_dcd_cap_in_pl {
> + uint32_t num_entries_updated;
> + uint8_t rsvd[4];
> + struct {
> + uint64_t start_dpa;
> + uint64_t len;
> + uint8_t rsvd[8];
> + } QEMU_PACKED updated_entries[];
> + } QEMU_PACKED;
> +
> + struct release_dcd_cap_in_pl *in = (void *)cmd->payload;
> + struct CXLType3Dev *ct3d = container_of(cxl_dstate, CXLType3Dev,
> cxl_dstate);
> + CXLDCDExtentList *extent_list = &ct3d->dc.extents;
> + CXLDCD_Extent *ent;
> + uint32_t i;
> + uint64_t dpa, len;
> + CXLRetCode rs;
> +
> + if (in->num_entries_updated == 0)
> + return CXL_MBOX_INVALID_INPUT;
> +
> + rs = detect_malformed_extent_list(ct3d, in);
> + if (rs != CXL_MBOX_SUCCESS)
> + return rs;
> +
> + /* Todo: check following
> + * One or more of the updated extent lists contain Starting DPA
> + * or Lengths that are out of range of a current extent list
> + * maintained by the device.
> + **/
> +
> + for (i = 0; i < in->num_entries_updated; i++) {
> + dpa = in->updated_entries[i].start_dpa;
> + len = in->updated_entries[i].len;
> +
> + QTAILQ_FOREACH(ent, extent_list, node) {
> + if (ent->start_dpa == dpa && ent->len == len)
Do the remove here and comment on 'found entry' not needed.
Note I think you can release partial extents so that will need handling at some
point.
> + break;
> + else if ((dpa < ent->start_dpa + ent->len
> + && dpa + len > ent->start_dpa + ent->len)
> + || (dpa < ent->start_dpa && dpa + len >
> ent->start_dpa))
Comment on this condition and why it's a problem.
> + return CXL_MBOX_INVALID_EXTENT_LIST;
> + }
> + /* found the entry, release it */
> + if (ent)
> + QTAILQ_REMOVE(extent_list, ent, node);
> + }
> +
> + return CXL_MBOX_SUCCESS;
> +}
> +
> #define IMMEDIATE_CONFIG_CHANGE (1 << 1)
> #define IMMEDIATE_DATA_CHANGE (1 << 2)
> #define IMMEDIATE_POLICY_CHANGE (1 << 3)
> @@ -1112,6 +1329,12 @@ static struct cxl_cmd cxl_cmd_set[256][256] = {
> [DCD_CONFIG][GET_DYN_CAP_EXT_LIST] = {
> "DCD_GET_DYNAMIC_CAPACITY_EXTENT_LIST",
> cmd_dcd_get_dyn_cap_ext_list,
> 8, 0 },
> + [DCD_CONFIG][ADD_DYN_CAP_RSP] = {
> + "ADD_DCD_DYNAMIC_CAPACITY_RESPONSE", cmd_dcd_add_dyn_cap_rsp,
> + ~0, IMMEDIATE_DATA_CHANGE },
> + [DCD_CONFIG][RELEASE_DYN_CAP] = {
> + "RELEASE_DCD_DYNAMIC_CAPACITY", cmd_dcd_release_dcd_capacity,
> + ~0, IMMEDIATE_DATA_CHANGE },
> };
>
> static struct cxl_cmd cxl_cmd_set_sw[256][256] = {
> diff --git a/include/hw/cxl/cxl_device.h b/include/hw/cxl/cxl_device.h
> index 20ad5e7411..c0c8fcc24b 100644
> --- a/include/hw/cxl/cxl_device.h
> +++ b/include/hw/cxl/cxl_device.h
> @@ -131,7 +131,8 @@ typedef enum {
> CXL_MBOX_INCORRECT_PASSPHRASE = 0x14,
> CXL_MBOX_UNSUPPORTED_MAILBOX = 0x15,
> CXL_MBOX_INVALID_PAYLOAD_LENGTH = 0x16,
> - CXL_MBOX_MAX = 0x17
> + CXL_MBOX_INVALID_EXTENT_LIST = 0x17,
0x1e in the spec.
> + CXL_MBOX_MAX = 0x18
> } CXLRetCode;
>
> struct cxl_cmd;