hw/misc/aspeed_hace: Remove unused code for better readability

In the previous design of the hash framework, accumulative hashing was not
supported. To work around this limitation, commit 5cd7d85 introduced an
iov_cache array to store all the hash data from firmware.
Once the ASPEED HACE model collected all the data, it passed the iov_cache to
the hash API to calculate the final digest.

However, with commit e3c0752, the hash framework now supports accumulative
hashing. This allows us to refactor the ASPEED HACE model, removing redundant
logic and simplifying the implementation for better readability and
maintainability.

As a result, the iov_count variable is no longer needed—it was previously used
to track how many cached entries were used for hashing.
To maintain VMSTATE compatibility after removing this field, the VMSTATE_VERSION
is bumped to 2

This cleanup follows significant changes in commit 4c1d0af4a2, making the
model more readable.

- Deleted "iov_cache" and "iov_count" from "AspeedHACEState".
- Removed "reconstruct_iov" function and related logic.
- Simplified "do_hash_operation" by eliminating redundant checks.

Signed-off-by: Jamin Lin <jamin_lin@aspeedtech.com>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250515081008.583578-2-jamin_lin@aspeedtech.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/misc/aspeed_hace.c

@@ -142,25 +142,6 @@ static bool has_padding(AspeedHACEState *s, struct iovec *iov,
     return false;
 }
 
-static int reconstruct_iov(AspeedHACEState *s, struct iovec *iov, int id,
-                           uint32_t *pad_offset)
-{
-    int i, iov_count;
-    if (*pad_offset != 0) {
-        s->iov_cache[s->iov_count].iov_base = iov[id].iov_base;
-        s->iov_cache[s->iov_count].iov_len = *pad_offset;
-        ++s->iov_count;
-    }
-    for (i = 0; i < s->iov_count; i++) {
-        iov[i].iov_base = s->iov_cache[i].iov_base;
-        iov[i].iov_len = s->iov_cache[i].iov_len;
-    }
-    iov_count = s->iov_count;
-    s->iov_count = 0;
-    s->total_req_len = 0;
-    return iov_count;
-}
-
 static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode,
                               bool acc_mode)
 {
@@ -242,19 +223,6 @@ static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode,
         iov[0].iov_base = haddr;
         iov[0].iov_len = len;
         i = 1;
-
-        if (s->iov_count) {
-            /*
-             * In aspeed sdk kernel driver, sg_mode is disabled in hash_final().
-             * Thus if we received a request with sg_mode disabled, it is
-             * required to check whether cache is empty. If no, we should
-             * combine cached iov and the current iov.
-             */
-            s->total_req_len += len;
-            if (has_padding(s, iov, len, &total_msg_len, &pad_offset)) {
-                i = reconstruct_iov(s, iov, 0, &pad_offset);
-            }
-        }
     }
 
     if (acc_mode) {
@@ -278,7 +246,6 @@ static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode,
             qcrypto_hash_free(s->hash_ctx);
 
             s->hash_ctx = NULL;
-            s->iov_count = 0;
             s->total_req_len = 0;
         }
     } else if (qcrypto_hash_bytesv(algo, iov, i, &digest_buf,
@@ -437,7 +404,6 @@ static void aspeed_hace_reset(DeviceState *dev)
     }
 
     memset(s->regs, 0, sizeof(s->regs));
-    s->iov_count = 0;
     s->total_req_len = 0;
 }
 
@@ -469,12 +435,11 @@ static const Property aspeed_hace_properties[] = {
 
 static const VMStateDescription vmstate_aspeed_hace = {
     .name = TYPE_ASPEED_HACE,
-    .version_id = 1,
+    .version_id = 2,
-    .minimum_version_id = 1,
+    .minimum_version_id = 2,
     .fields = (const VMStateField[]) {
         VMSTATE_UINT32_ARRAY(regs, AspeedHACEState, ASPEED_HACE_NR_REGS),
         VMSTATE_UINT32(total_req_len, AspeedHACEState),
-        VMSTATE_UINT32(iov_count, AspeedHACEState),
         VMSTATE_END_OF_LIST(),
     }
 };

include/hw/misc/aspeed_hace.h

@@ -31,10 +31,8 @@ struct AspeedHACEState {
     MemoryRegion iomem;
     qemu_irq irq;
 
-    struct iovec iov_cache[ASPEED_HACE_MAX_SG];
     uint32_t regs[ASPEED_HACE_NR_REGS];
     uint32_t total_req_len;
-    uint32_t iov_count;
 
     MemoryRegion *dram_mr;
     AddressSpace dram_as;