From b6c636f2cd6c50cdc558e3c02fbc7f2d102955b2 Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Tue, 3 Sep 2019 10:39:49 +0200 Subject: s390x/tcg: Fault-safe memmove Replace fast_memmove() variants by access_memmove() variants, that first try to probe access to all affected pages (maximum is two pages). Introduce access_get_byte()/access_set_byte(). We might be able to speed up memmove in special cases even further (do single-byte access, use memmove() for remaining bytes in page), however, we'll skip that for now. In MVCOS, simply always call access_memmove_as() and drop the TODO about LAP. LAP is already handled in the MMU. Get rid of adj_len_to_page(), which is now unused. Reviewed-by: Richard Henderson Signed-off-by: David Hildenbrand --- target/s390x/mem_helper.c | 238 +++++++++++++++++++++++++++------------------- 1 file changed, 139 insertions(+), 99 deletions(-) diff --git a/target/s390x/mem_helper.c b/target/s390x/mem_helper.c index dd5da70746..12ffe72c88 100644 --- a/target/s390x/mem_helper.c +++ b/target/s390x/mem_helper.c @@ -65,17 +65,6 @@ static bool is_destructive_overlap(CPUS390XState *env, uint64_t dest, return dest > src && dest <= src + len - 1; } -/* Reduce the length so that addr + len doesn't cross a page boundary. */ -static inline uint32_t adj_len_to_page(uint32_t len, uint64_t addr) -{ -#ifndef CONFIG_USER_ONLY - if ((addr & ~TARGET_PAGE_MASK) + len - 1 >= TARGET_PAGE_SIZE) { - return -(addr | TARGET_PAGE_MASK); - } -#endif - return len; -} - /* Trigger a SPECIFICATION exception if an address or a length is not naturally aligned. */ static inline void check_alignment(CPUS390XState *env, uint64_t v, @@ -208,39 +197,116 @@ static void access_memset(CPUS390XState *env, S390Access *desta, desta->mmu_idx, ra); } -#ifndef CONFIG_USER_ONLY -static void fast_memmove_idx(CPUS390XState *env, uint64_t dest, uint64_t src, - uint32_t len, int dest_idx, int src_idx, - uintptr_t ra) +static uint8_t do_access_get_byte(CPUS390XState *env, vaddr vaddr, char **haddr, + int offset, int mmu_idx, uintptr_t ra) { - TCGMemOpIdx oi_dest = make_memop_idx(MO_UB, dest_idx); - TCGMemOpIdx oi_src = make_memop_idx(MO_UB, src_idx); - uint32_t len_adj; - void *src_p; - void *dest_p; - uint8_t x; - - while (len > 0) { - src = wrap_address(env, src); - dest = wrap_address(env, dest); - src_p = tlb_vaddr_to_host(env, src, MMU_DATA_LOAD, src_idx); - dest_p = tlb_vaddr_to_host(env, dest, MMU_DATA_STORE, dest_idx); - - if (src_p && dest_p) { - /* Access to both whole pages granted. */ - len_adj = adj_len_to_page(adj_len_to_page(len, src), dest); - memmove(dest_p, src_p, len_adj); - } else { - /* We failed to get access to one or both whole pages. The next - read or write access will likely fill the QEMU TLB for the - next iteration. */ - len_adj = 1; - x = helper_ret_ldub_mmu(env, src, oi_src, ra); - helper_ret_stb_mmu(env, dest, x, oi_dest, ra); +#ifdef CONFIG_USER_ONLY + return ldub_p(*haddr + offset); +#else + TCGMemOpIdx oi = make_memop_idx(MO_UB, mmu_idx); + uint8_t byte; + + if (likely(*haddr)) { + return ldub_p(*haddr + offset); + } + /* + * Do a single access and test if we can then get access to the + * page. This is especially relevant to speed up TLB_NOTDIRTY. + */ + byte = helper_ret_ldub_mmu(env, vaddr + offset, oi, ra); + *haddr = tlb_vaddr_to_host(env, vaddr, MMU_DATA_LOAD, mmu_idx); + return byte; +#endif +} + +static uint8_t access_get_byte(CPUS390XState *env, S390Access *access, + int offset, uintptr_t ra) +{ + if (offset < access->size1) { + return do_access_get_byte(env, access->vaddr1, &access->haddr1, + offset, access->mmu_idx, ra); + } + return do_access_get_byte(env, access->vaddr2, &access->haddr2, + offset - access->size1, access->mmu_idx, ra); +} + +static void do_access_set_byte(CPUS390XState *env, vaddr vaddr, char **haddr, + int offset, uint8_t byte, int mmu_idx, + uintptr_t ra) +{ +#ifdef CONFIG_USER_ONLY + stb_p(*haddr + offset, byte); +#else + TCGMemOpIdx oi = make_memop_idx(MO_UB, mmu_idx); + + if (likely(*haddr)) { + stb_p(*haddr + offset, byte); + return; + } + /* + * Do a single access and test if we can then get access to the + * page. This is especially relevant to speed up TLB_NOTDIRTY. + */ + helper_ret_stb_mmu(env, vaddr + offset, byte, oi, ra); + *haddr = tlb_vaddr_to_host(env, vaddr, MMU_DATA_STORE, mmu_idx); +#endif +} + +static void access_set_byte(CPUS390XState *env, S390Access *access, + int offset, uint8_t byte, uintptr_t ra) +{ + if (offset < access->size1) { + do_access_set_byte(env, access->vaddr1, &access->haddr1, offset, byte, + access->mmu_idx, ra); + } else { + do_access_set_byte(env, access->vaddr2, &access->haddr2, + offset - access->size1, byte, access->mmu_idx, ra); + } +} + +/* + * Move data with the same semantics as memmove() in case ranges don't overlap + * or src > dest. Undefined behavior on destructive overlaps. + */ +static void access_memmove(CPUS390XState *env, S390Access *desta, + S390Access *srca, uintptr_t ra) +{ + int diff; + + g_assert(desta->size1 + desta->size2 == srca->size1 + srca->size2); + + /* Fallback to slow access in case we don't have access to all host pages */ + if (unlikely(!desta->haddr1 || (desta->size2 && !desta->haddr2) || + !srca->haddr1 || (srca->size2 && !srca->haddr2))) { + int i; + + for (i = 0; i < desta->size1 + desta->size2; i++) { + uint8_t byte = access_get_byte(env, srca, i, ra); + + access_set_byte(env, desta, i, byte, ra); + } + return; + } + + if (srca->size1 == desta->size1) { + memmove(desta->haddr1, srca->haddr1, srca->size1); + if (unlikely(srca->size2)) { + memmove(desta->haddr2, srca->haddr2, srca->size2); + } + } else if (srca->size1 < desta->size1) { + diff = desta->size1 - srca->size1; + memmove(desta->haddr1, srca->haddr1, srca->size1); + memmove(desta->haddr1 + srca->size1, srca->haddr2, diff); + if (likely(desta->size2)) { + memmove(desta->haddr2, srca->haddr2 + diff, desta->size2); + } + } else { + diff = srca->size1 - desta->size1; + memmove(desta->haddr1, srca->haddr1, desta->size1); + memmove(desta->haddr2, srca->haddr1 + desta->size1, diff); + if (likely(srca->size2)) { + memmove(desta->haddr2 + diff, srca->haddr2, srca->size2); } - src += len_adj; - dest += len_adj; - len -= len_adj; } } @@ -259,45 +325,6 @@ static int mmu_idx_from_as(uint8_t as) } } -static void fast_memmove_as(CPUS390XState *env, uint64_t dest, uint64_t src, - uint32_t len, uint8_t dest_as, uint8_t src_as, - uintptr_t ra) -{ - int src_idx = mmu_idx_from_as(src_as); - int dest_idx = mmu_idx_from_as(dest_as); - - fast_memmove_idx(env, dest, src, len, dest_idx, src_idx, ra); -} -#endif - -static void fast_memmove(CPUS390XState *env, uint64_t dest, uint64_t src, - uint32_t l, uintptr_t ra) -{ - int mmu_idx = cpu_mmu_index(env, false); - - while (l > 0) { - void *src_p = tlb_vaddr_to_host(env, src, MMU_DATA_LOAD, mmu_idx); - void *dest_p = tlb_vaddr_to_host(env, dest, MMU_DATA_STORE, mmu_idx); - if (src_p && dest_p) { - /* Access to both whole pages granted. */ - uint32_t l_adj = adj_len_to_page(l, src); - l_adj = adj_len_to_page(l_adj, dest); - memmove(dest_p, src_p, l_adj); - src += l_adj; - dest += l_adj; - l -= l_adj; - } else { - /* We failed to get access to one or both whole pages. The next - read or write access will likely fill the QEMU TLB for the - next iteration. */ - cpu_stb_data_ra(env, dest, cpu_ldub_data_ra(env, src, ra), ra); - src++; - dest++; - l--; - } - } -} - /* and on array */ static uint32_t do_helper_nc(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src, uintptr_t ra) @@ -388,7 +415,7 @@ static uint32_t do_helper_mvc(CPUS390XState *env, uint32_t l, uint64_t dest, uint64_t src, uintptr_t ra) { const int mmu_idx = cpu_mmu_index(env, false); - S390Access desta; + S390Access srca, desta; uint32_t i; HELPER_LOG("%s l %d dest %" PRIx64 " src %" PRIx64 "\n", @@ -397,6 +424,7 @@ static uint32_t do_helper_mvc(CPUS390XState *env, uint32_t l, uint64_t dest, /* MVC always copies one more byte than specified - maximum is 256 */ l++; + srca = access_prepare(env, src, l, MMU_DATA_LOAD, mmu_idx, ra); desta = access_prepare(env, dest, l, MMU_DATA_STORE, mmu_idx, ra); /* @@ -405,9 +433,9 @@ static uint32_t do_helper_mvc(CPUS390XState *env, uint32_t l, uint64_t dest, * behave like memmove(). */ if (dest == src + 1) { - access_memset(env, &desta, cpu_ldub_data_ra(env, src, ra), ra); + access_memset(env, &desta, access_get_byte(env, &srca, 0, ra), ra); } else if (!is_destructive_overlap(env, dest, src, l)) { - fast_memmove(env, dest, src, l, ra); + access_memmove(env, &desta, &srca, ra); } else { for (i = 0; i < l; i++) { uint8_t x = cpu_ldub_data_ra(env, src + i, ra); @@ -756,8 +784,11 @@ uint64_t HELPER(clst)(CPUS390XState *env, uint64_t c, uint64_t s1, uint64_t s2) /* move page */ uint32_t HELPER(mvpg)(CPUS390XState *env, uint64_t r0, uint64_t r1, uint64_t r2) { + const int mmu_idx = cpu_mmu_index(env, false); const bool f = extract64(r0, 11, 1); const bool s = extract64(r0, 10, 1); + uintptr_t ra = GETPC(); + S390Access srca, desta; if ((f && s) || extract64(r0, 12, 4)) { s390_program_interrupt(env, PGM_SPECIFICATION, ILEN_AUTO, GETPC()); @@ -772,7 +803,11 @@ uint32_t HELPER(mvpg)(CPUS390XState *env, uint64_t r0, uint64_t r1, uint64_t r2) * - CC-option with surpression of page-translation exceptions * - Store r1/r2 register identifiers at real location 162 */ - fast_memmove(env, r1, r2, TARGET_PAGE_SIZE, GETPC()); + srca = access_prepare(env, r2, TARGET_PAGE_SIZE, MMU_DATA_LOAD, mmu_idx, + ra); + desta = access_prepare(env, r1, TARGET_PAGE_SIZE, MMU_DATA_STORE, mmu_idx, + ra); + access_memmove(env, &desta, &srca, ra); return 0; /* data moved */ } @@ -853,7 +888,7 @@ static inline uint32_t do_mvcl(CPUS390XState *env, { const int mmu_idx = cpu_mmu_index(env, false); int len = MIN(*destlen, -(*dest | TARGET_PAGE_MASK)); - S390Access desta; + S390Access srca, desta; int i, cc; if (*destlen == *srclen) { @@ -877,7 +912,9 @@ static inline uint32_t do_mvcl(CPUS390XState *env, len = MIN(MIN(*srclen, -(*src | TARGET_PAGE_MASK)), len); *destlen -= len; *srclen -= len; - fast_memmove(env, *dest, *src, len, ra); + srca = access_prepare(env, *src, len, MMU_DATA_LOAD, mmu_idx, ra); + desta = access_prepare(env, *dest, len, MMU_DATA_STORE, mmu_idx, ra); + access_memmove(env, &desta, &srca, ra); *src = wrap_address(env, *src + len); *dest = wrap_address(env, *dest + len); } else if (wordsize == 1) { @@ -911,8 +948,8 @@ uint32_t HELPER(mvcl)(CPUS390XState *env, uint32_t r1, uint32_t r2) uint64_t srclen = env->regs[r2 + 1] & 0xffffff; uint64_t src = get_address(env, r2); uint8_t pad = env->regs[r2 + 1] >> 24; + S390Access srca, desta; uint32_t cc, cur_len; - S390Access desta; if (is_destructive_overlap(env, dest, src, MIN(srclen, destlen))) { cc = 3; @@ -946,7 +983,11 @@ uint32_t HELPER(mvcl)(CPUS390XState *env, uint32_t r1, uint32_t r2) } else { cur_len = MIN(MIN(srclen, -(src | TARGET_PAGE_MASK)), cur_len); - fast_memmove(env, dest, src, cur_len, ra); + srca = access_prepare(env, src, cur_len, MMU_DATA_LOAD, mmu_idx, + ra); + desta = access_prepare(env, dest, cur_len, MMU_DATA_STORE, mmu_idx, + ra); + access_memmove(env, &desta, &srca, ra); src = wrap_address(env, src + cur_len); srclen -= cur_len; env->regs[r2 + 1] = deposit64(env->regs[r2 + 1], 0, 24, srclen); @@ -2488,16 +2529,15 @@ uint32_t HELPER(mvcos)(CPUS390XState *env, uint64_t dest, uint64_t src, s390_program_interrupt(env, PGM_ADDRESSING, 6, ra); } - /* FIXME: a) LAP - * b) Access using correct keys - * c) AR-mode - */ -#ifdef CONFIG_USER_ONLY - /* psw keys are never valid in user mode, we will never reach this */ - g_assert_not_reached(); -#else - fast_memmove_as(env, dest, src, len, dest_as, src_as, ra); -#endif + /* FIXME: Access using correct keys and AR-mode */ + if (len) { + S390Access srca = access_prepare(env, src, len, MMU_DATA_LOAD, + mmu_idx_from_as(src_as), ra); + S390Access desta = access_prepare(env, dest, len, MMU_DATA_STORE, + mmu_idx_from_as(dest_as), ra); + + access_memmove(env, &desta, &srca, ra); + } return cc; } -- cgit v1.2.3