[PATCH 4/5] hw/cxl: Add support for device sanitation

[Davidlohr Bueso <dave@stgolabs.net>]

Make use of the background operations through the sanitize
command, per CXL 3.0 specs. Traditionally run times can be
rather long, depending on the size of the media.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
---
 hw/cxl/cxl-mailbox-utils.c | 125 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 124 insertions(+), 1 deletion(-)

diff --git a/hw/cxl/cxl-mailbox-utils.c b/hw/cxl/cxl-mailbox-utils.c
index e0e20bc3a2bb..2808d0161a38 100644
--- a/hw/cxl/cxl-mailbox-utils.c
+++ b/hw/cxl/cxl-mailbox-utils.c
@@ -18,6 +18,7 @@
 #include "qemu/log.h"
 #include "qemu/units.h"
 #include "qemu/uuid.h"
+#include "sysemu/hostmem.h"
 
 #define CXL_CAPACITY_MULTIPLIER   (256 * MiB)
 
@@ -71,6 +72,9 @@ enum {
         #define GET_PARTITION_INFO     0x0
         #define GET_LSA       0x2
         #define SET_LSA       0x3
+    SANITATION    = 0x44,
+        #define SANITIZE      0x0
+        #define SECURE_ERASE  0x1
     MEDIA_AND_POISON = 0x43,
         #define GET_POISON_LIST        0x0
         #define INJECT_POISON          0x1
@@ -819,6 +823,112 @@ static CXLRetCode cmd_media_clear_poison(struct cxl_cmd *cmd,
 #define IMMEDIATE_LOG_CHANGE (1 << 4)
 #define BACKGROUND_OPERATION (1 << 5)
 
+/* re-initialize the address space */
+static void __do_sanitization(CXLDeviceState *cxl_dstate)
+{
+    CXLType3Dev *ct3d = container_of(cxl_dstate, CXLType3Dev, cxl_dstate);
+    DeviceState *ds = DEVICE(ct3d);
+    char *name;
+    MemoryRegion *mr;
+
+    if (ct3d->hostvmem) {
+        mr = host_memory_backend_get_memory(ct3d->hostvmem);
+        if (!mr) {
+            return;
+        }
+        if (ds->id) {
+            name = g_strdup_printf("cxl-type3-dpa-vmem-space:%s", ds->id);
+        } else {
+            name = g_strdup("cxl-type3-dpa-vmem-space");
+        }
+
+        address_space_destroy(&ct3d->hostvmem_as);
+        address_space_init(&ct3d->hostvmem_as, mr, name);
+        g_free(name);
+    }
+    if (ct3d->hostpmem) {
+        mr = host_memory_backend_get_memory(ct3d->hostpmem);
+        if (!mr) {
+            return;
+        }
+        if (ds->id) {
+            name = g_strdup_printf("cxl-type3-dpa-pmem-space:%s", ds->id);
+        } else {
+            name = g_strdup("cxl-type3-dpa-pmem-space");
+        }
+
+        address_space_destroy(&ct3d->hostpmem_as);
+        address_space_init(&ct3d->hostpmem_as, mr, name);
+        g_free(name);
+    }
+}
+
+/*
+ * CXL 3.0 spec section 8.2.9.8.5.1 - Sanitize.
+ *
+ * Once the Sanitize command has started successfully, the device shall
+ * shall be placed in the media disabled state. If the command fails or
+ * is interrupted by a reset or power failure, it shall remain in the
+ * media disabled state until a successful Sanitize command has been
+ * completed.
+ */
+static CXLRetCode cmd_sanitation_sanitize(struct cxl_cmd *cmd,
+                                          CXLDeviceState *cxl_dstate,
+                                          uint16_t *len)
+{
+    unsigned int secs;
+    uint64_t total_mem; /* in Mb */
+    struct cxl_cmd *c;
+
+    *len = 0;
+
+    /* Reported in CEL */
+    c = &cxl_dstate->cxl_cmd_set[SANITATION][SANITIZE];
+    if (!(c->effect & BACKGROUND_OPERATION)) {
+        __do_sanitization(cxl_dstate);
+        return CXL_MBOX_SUCCESS;
+    }
+
+    /*
+     * Estimated times based on:
+     *     https://pmem.io/documents/NVDIMM_DSM_Interface-V1.8.pdf
+     */
+    total_mem = (cxl_dstate->vmem_size + cxl_dstate->pmem_size) >> 20;
+    if (total_mem <= 512) {
+        secs = 4;
+    } else if (total_mem <= 1024) {
+        secs = 8;
+    } else if (total_mem <= 2 * 1024) {
+        secs = 15;
+    } else if (total_mem <= 4 * 1024) {
+        secs = 30;
+    } else if (total_mem <= 8 * 1024) {
+        secs = 60;
+    } else if (total_mem <= 16 * 1024) {
+        secs = 2 * 60;
+    } else if (total_mem <= 32 * 1024) {
+        secs = 4 * 60;
+    } else if (total_mem <= 64 * 1024) {
+        secs = 8 * 60;
+    } else if (total_mem <= 128 * 1024) {
+        secs = 15 * 60;
+    } else if (total_mem <= 256 * 1024) {
+        secs = 30 * 60;
+    } else if (total_mem <= 512 * 1024) {
+        secs = 60 * 60;
+    } else if (total_mem <= 1024 * 1024) {
+        secs = 120 * 60;
+    } else {
+        secs = 240 * 60; /* max 4 hrs */
+    }
+
+    /* sanitize when done */
+    cxl_dev_media_disable(cxl_dstate);
+    cxl_dstate->bg.runtime = secs * 1000UL;
+
+    return CXL_MBOX_BG_STARTED;
+}
+
 static struct cxl_cmd cxl_cmd_set[256][256] = {
     [EVENTS][GET_RECORDS] = { "EVENTS_GET_RECORDS",
         cmd_events_get_records, 1, 0 },
@@ -842,6 +952,8 @@ static struct cxl_cmd cxl_cmd_set[256][256] = {
     [CCLS][GET_LSA] = { "CCLS_GET_LSA", cmd_ccls_get_lsa, 8, 0 },
     [CCLS][SET_LSA] = { "CCLS_SET_LSA", cmd_ccls_set_lsa,
         ~0, IMMEDIATE_CONFIG_CHANGE | IMMEDIATE_DATA_CHANGE },
+    [SANITATION][SANITIZE] = { "SANITATION_SANITIZE", cmd_sanitation_sanitize,
+        0, IMMEDIATE_DATA_CHANGE | BACKGROUND_OPERATION },
     [MEDIA_AND_POISON][GET_POISON_LIST] = { "MEDIA_AND_POISON_GET_POISON_LIST",
         cmd_media_get_poison_list, 16, 0 },
     [MEDIA_AND_POISON][INJECT_POISON] = { "MEDIA_AND_POISON_INJECT_POISON",
@@ -985,7 +1097,18 @@ static void bg_timercb(void *opaque)
 
         bg_status_reg = FIELD_DP64(bg_status_reg, CXL_DEV_BG_CMD_STS, RET_CODE, ret);
 
-        /* TODO add ad-hoc cmd succesful completion handling */
+        /* ad-hoc cmd succesful completion handling */
+        if (ret == CXL_MBOX_SUCCESS) {
+            switch (cxl_dstate->bg.opcode) {
+            case 0x4400: /* sanitize */
+                __do_sanitization(cxl_dstate);
+                cxl_dev_media_enable(cxl_dstate);
+                break;
+            default:
+                __builtin_unreachable();
+                break;
+            }
+        }
     } else {
         /* estimate only */
         cxl_dstate->bg.complete_pct = 100 * now / total_time;
-- 
2.40.0