diff options
| -rw-r--r-- | accel/tcg/translate-all.c | 2 | ||||
| -rw-r--r-- | include/exec/cpu-all.h | 6 | ||||
| -rw-r--r-- | linux-user/mmap.c | 27 |
3 files changed, 29 insertions, 6 deletions
diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index f5e8592..d71d04d 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -2258,7 +2258,7 @@ int page_get_flags(target_ulong address) #ifndef PAGE_TARGET_STICKY #define PAGE_TARGET_STICKY 0 #endif -#define PAGE_STICKY (PAGE_ANON | PAGE_TARGET_STICKY) +#define PAGE_STICKY (PAGE_ANON | PAGE_PASSTHROUGH | PAGE_TARGET_STICKY) /* Modify the flags of a page and invalidate the code if necessary. The flag PAGE_WRITE_ORG is positioned automatically depending diff --git a/include/exec/cpu-all.h b/include/exec/cpu-all.h index 491629b..16b7df4 100644 --- a/include/exec/cpu-all.h +++ b/include/exec/cpu-all.h @@ -262,6 +262,12 @@ extern const TargetPageBits target_page; #define PAGE_TARGET_1 0x0200 #define PAGE_TARGET_2 0x0400 +/* + * For linux-user, indicates that the page is mapped with the same semantics + * in both guest and host. + */ +#define PAGE_PASSTHROUGH 0x0800 + #if defined(CONFIG_USER_ONLY) void page_dump(FILE *f); diff --git a/linux-user/mmap.c b/linux-user/mmap.c index 942bec7..e557f36 100644 --- a/linux-user/mmap.c +++ b/linux-user/mmap.c @@ -431,7 +431,8 @@ abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size, abi_ulong align) abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, int flags, int fd, abi_ulong offset) { - abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len; + abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len, + passthrough_start = -1, passthrough_end = -1; int page_flags, host_prot; mmap_lock(); @@ -544,6 +545,8 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, host_start += offset - host_offset; } start = h2g(host_start); + passthrough_start = start; + passthrough_end = start + len; } else { if (start & ~TARGET_PAGE_MASK) { errno = EINVAL; @@ -626,6 +629,8 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, host_prot, flags, fd, offset1); if (p == MAP_FAILED) goto fail; + passthrough_start = real_start; + passthrough_end = real_end; } } the_end1: @@ -633,7 +638,18 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int target_prot, page_flags |= PAGE_ANON; } page_flags |= PAGE_RESET; - page_set_flags(start, start + len, page_flags); + if (passthrough_start == passthrough_end) { + page_set_flags(start, start + len, page_flags); + } else { + if (start < passthrough_start) { + page_set_flags(start, passthrough_start, page_flags); + } + page_set_flags(passthrough_start, passthrough_end, + page_flags | PAGE_PASSTHROUGH); + if (passthrough_end < start + len) { + page_set_flags(passthrough_end, start + len, page_flags); + } + } the_end: trace_target_mmap_complete(start); if (qemu_loglevel_mask(CPU_LOG_PAGE)) { @@ -852,7 +868,7 @@ static bool can_passthrough_madv_dontneed(abi_ulong start, abi_ulong end) } for (addr = start; addr < end; addr += TARGET_PAGE_SIZE) { - if (!(page_get_flags(addr) & PAGE_ANON)) { + if (!(page_get_flags(addr) & PAGE_PASSTHROUGH)) { return false; } } @@ -894,8 +910,9 @@ abi_long target_madvise(abi_ulong start, abi_ulong len_in, int advice) * This is a hint, so ignoring and returning success is ok. * * This breaks MADV_DONTNEED, completely implementing which is quite - * complicated. However, there is one low-hanging fruit: host-page-aligned - * anonymous mappings. In this case passthrough is safe, so do it. + * complicated. However, there is one low-hanging fruit: mappings that are + * known to have the same semantics in the host and the guest. In this case + * passthrough is safe, so do it. */ mmap_lock(); if (advice == TARGET_MADV_DONTNEED && |