On 24.08.19 23:34, Richard Henderson wrote:
> We want to move the check for watchpoints from
> memory_region_section_get_iotlb to tlb_set_page_with_attrs.
> Isolate the loop over watchpoints to an exported function.
>
> Rename the existing cpu_watchpoint_address_matches to
> watchpoint_address_matches, since it doesn't actually
> have a cpu argument.
>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> include/hw/core/cpu.h | 7 +++++++
> exec.c | 45 ++++++++++++++++++++++++++++---------------
> 2 files changed, 36 insertions(+), 16 deletions(-)
>
> diff --git a/include/hw/core/cpu.h b/include/hw/core/cpu.h
> index 7bd8bed5b2..c7cda65c66 100644
> --- a/include/hw/core/cpu.h
> +++ b/include/hw/core/cpu.h
> @@ -1096,6 +1096,12 @@ static inline void cpu_check_watchpoint(CPUState *cpu,
> vaddr addr, vaddr len,
> MemTxAttrs atr, int fl, uintptr_t ra)
> {
> }
> +
> +static inline int cpu_watchpoint_address_matches(CPUState *cpu,
> + vaddr addr, vaddr len)
> +{
> + return 0;
> +}
> #else
> int cpu_watchpoint_insert(CPUState *cpu, vaddr addr, vaddr len,
> int flags, CPUWatchpoint **watchpoint);
> @@ -1105,6 +1111,7 @@ void cpu_watchpoint_remove_by_ref(CPUState *cpu,
> CPUWatchpoint *watchpoint);
> void cpu_watchpoint_remove_all(CPUState *cpu, int mask);
> void cpu_check_watchpoint(CPUState *cpu, vaddr addr, vaddr len,
> MemTxAttrs attrs, int flags, uintptr_t ra);
> +int cpu_watchpoint_address_matches(CPUState *cpu, vaddr addr, vaddr len);
> #endif
>
> /**
> diff --git a/exec.c b/exec.c
> index cb6f5763dc..8575ce51ad 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1138,9 +1138,8 @@ void cpu_watchpoint_remove_all(CPUState *cpu, int mask)
> * partially or completely with the address range covered by the
> * access).
> */
> -static inline bool cpu_watchpoint_address_matches(CPUWatchpoint *wp,
> - vaddr addr,
> - vaddr len)
> +static inline bool watchpoint_address_matches(CPUWatchpoint *wp,
> + vaddr addr, vaddr len)
> {
> /* We know the lengths are non-zero, but a little caution is
> * required to avoid errors in the case where the range ends
> @@ -1152,6 +1151,20 @@ static inline bool
> cpu_watchpoint_address_matches(CPUWatchpoint *wp,
>
> return !(addr > wpend || wp->vaddr > addrend);
> }
> +
> +/* Return flags for watchpoints that match addr + prot. */
> +int cpu_watchpoint_address_matches(CPUState *cpu, vaddr addr, vaddr len)
> +{
> + CPUWatchpoint *wp;
> + int ret = 0;
> +
> + QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
> + if (watchpoint_address_matches(wp, addr, TARGET_PAGE_SIZE)) {
> + ret |= wp->flags;
> + }
> + }
> + return ret;
> +}
> #endif /* !CONFIG_USER_ONLY */
>
> /* Add a breakpoint. */
> @@ -1459,7 +1472,7 @@ hwaddr memory_region_section_get_iotlb(CPUState *cpu,
> target_ulong *address)
> {
> hwaddr iotlb;
> - CPUWatchpoint *wp;
> + int flags, match;
>
> if (memory_region_is_ram(section->mr)) {
> /* Normal RAM. */
> @@ -1477,17 +1490,17 @@ hwaddr memory_region_section_get_iotlb(CPUState *cpu,
> iotlb += xlat;
> }
>
> - /* Make accesses to pages with watchpoints go via the
> - watchpoint trap routines. */
> - QTAILQ_FOREACH(wp, &cpu->watchpoints, entry) {
> - if (cpu_watchpoint_address_matches(wp, vaddr, TARGET_PAGE_SIZE)) {
> - /* Avoid trapping reads of pages with a write breakpoint. */
> - if ((prot & PAGE_WRITE) || (wp->flags & BP_MEM_READ)) {
> - iotlb = PHYS_SECTION_WATCH + paddr;
> - *address |= TLB_MMIO;
> - break;
In the old code, we were able to break once we found a hit ...
> - }
> - }
> + /* Avoid trapping reads of pages with a write breakpoint. */
> + match = (prot & PAGE_READ ? BP_MEM_READ : 0)
> + | (prot & PAGE_WRITE ? BP_MEM_WRITE : 0);
> + flags = cpu_watchpoint_address_matches(cpu, vaddr, TARGET_PAGE_SIZE);
> + if (flags & match) {
... now you cannot break early anymore. Maybe pass in the match to
cpu_watchpoint_address_matches() ?
Anyhow, code seems to be correct, so
Reviewed-by: David Hildenbrand <da...@redhat.com>
--
Thanks,
David / dhildenb
