On 1/7/26 15:11, Richard Henderson wrote:
On 7/1/26 00:37, Philippe Mathieu-Daudé wrote:
(this is commit c647673ce4d72a8789703c62a7f3cbc732cb1ea8)
...
+ /* Probe the page(s). */
+ if (!sve_cont_ldst_pages(&info, fault, env, addr, MMU_DATA_LOAD,
retaddr)) {
+ /* Fault on first element. */
+ tcg_debug_assert(fault == FAULT_NO);
+ memset(vd, 0, reg_max);
+ goto do_fault;
+ }
+
+ mem_off = info.mem_off_first[0];
+ flags = info.page[0].flags;
+
+ if (fault == FAULT_FIRST) {
+ /*
+ * Special handling of the first active element,
+ * if it crosses a page boundary or is MMIO.
+ */
+ bool is_split = mem_off == info.mem_off_split;
+ /* TODO: MTE check. */
+ if (unlikely(flags != 0) || unlikely(is_split)) {
+ /*
+ * Use the slow path for cross-page handling.
+ * Might trap for MMIO or watchpoints.
+ */
+ tlb_fn(env, vd, reg_off, addr + mem_off, retaddr);
+
+ /* After any fault, zero the other elements. */
swap_memzero(vd, reg_off);
- return;
+ reg_off += 1 << esz;
+ mem_off += 1 << msz;
+ swap_memzero(vd + reg_off, reg_max - reg_off);
+
+ if (is_split) {
+ goto second_page;
+ }
+ } else {
+ memset(vd, 0, reg_max);
+ }
+ } else {
+ memset(vd, 0, reg_max);
+ if (unlikely(mem_off == info.mem_off_split)) {
Is this code reachable on user emulation? The changes are
quite complex, previously code was guarded with CONFIG_USER_ONLY.
Yes, if you mean this line specifically. This merely requires an
unaligned vector load that crosses pages.
Sorry for not being clear enough, I meant the TLB_MMIO & TLB_WATCHPOINT
checks just after:
+ /* The first active element crosses a page boundary. */
+ flags |= info.page[1].flags;
+ if (unlikely(flags & TLB_MMIO)) {
+ /* Some page is MMIO, see below. */
+ goto do_fault;
+ }
+ if (unlikely(flags & TLB_WATCHPOINT) &&
+ (cpu_watchpoint_address_matches
+ (env_cpu(env), addr + mem_off, 1 << msz)
+ & BP_MEM_READ)) {
+ /* Watchpoint hit, see below. */
+ goto do_fault;
+ }
+ /* TODO: MTE check. */
+ /*
+ * Use the slow path for cross-page handling.
+ * This is RAM, without a watchpoint, and will not trap.
+ */
+ tlb_fn(env, vd, reg_off, addr + mem_off, retaddr);
+ goto second_page;
}
}
