diff options
author | Richard Henderson <richard.henderson@linaro.org> | 2022-10-04 17:47:00 -0700 |
---|---|---|
committer | Richard Henderson <richard.henderson@linaro.org> | 2022-12-20 17:11:12 -0800 |
commit | d941c086b818533a9332272609405334e59a6f27 (patch) | |
tree | 7a688662ec64a3f7ed2cc3412bb847c3e588737f /accel | |
parent | 50d25c8aec3e495faee82f1732cc93f016967850 (diff) | |
download | qemu-d941c086b818533a9332272609405334e59a6f27.zip qemu-d941c086b818533a9332272609405334e59a6f27.tar.gz qemu-d941c086b818533a9332272609405334e59a6f27.tar.bz2 |
accel/tcg: Move page_{get,set}_flags to user-exec.c
This page tracking implementation is specific to user-only,
since the system softmmu version is in cputlb.c. Move it
out of translate-all.c to user-exec.c.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'accel')
-rw-r--r-- | accel/tcg/internal.h | 17 | ||||
-rw-r--r-- | accel/tcg/translate-all.c | 350 | ||||
-rw-r--r-- | accel/tcg/user-exec.c | 346 |
3 files changed, 363 insertions, 350 deletions
diff --git a/accel/tcg/internal.h b/accel/tcg/internal.h index 0f91ee9..ddd1fa6 100644 --- a/accel/tcg/internal.h +++ b/accel/tcg/internal.h @@ -33,6 +33,23 @@ typedef struct PageDesc { #endif } PageDesc; +/* + * In system mode we want L1_MAP to be based on ram offsets, + * while in user mode we want it to be based on virtual addresses. + * + * TODO: For user mode, see the caveat re host vs guest virtual + * address spaces near GUEST_ADDR_MAX. + */ +#if !defined(CONFIG_USER_ONLY) +#if HOST_LONG_BITS < TARGET_PHYS_ADDR_SPACE_BITS +# define L1_MAP_ADDR_SPACE_BITS HOST_LONG_BITS +#else +# define L1_MAP_ADDR_SPACE_BITS TARGET_PHYS_ADDR_SPACE_BITS +#endif +#else +# define L1_MAP_ADDR_SPACE_BITS MIN(HOST_LONG_BITS, TARGET_ABI_BITS) +#endif + /* Size of the L2 (and L3, etc) page tables. */ #define V_L2_BITS 10 #define V_L2_SIZE (1 << V_L2_BITS) diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 48e9d70..cc3ec36 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -109,23 +109,6 @@ struct page_collection { struct page_entry *max; }; -/* - * In system mode we want L1_MAP to be based on ram offsets, - * while in user mode we want it to be based on virtual addresses. - * - * TODO: For user mode, see the caveat re host vs guest virtual - * address spaces near GUEST_ADDR_MAX. - */ -#if !defined(CONFIG_USER_ONLY) -#if HOST_LONG_BITS < TARGET_PHYS_ADDR_SPACE_BITS -# define L1_MAP_ADDR_SPACE_BITS HOST_LONG_BITS -#else -# define L1_MAP_ADDR_SPACE_BITS TARGET_PHYS_ADDR_SPACE_BITS -#endif -#else -# define L1_MAP_ADDR_SPACE_BITS MIN(HOST_LONG_BITS, TARGET_ABI_BITS) -#endif - /* Make sure all possible CPU event bits fit in tb->trace_vcpu_dstate */ QEMU_BUILD_BUG_ON(CPU_TRACE_DSTATE_MAX_EVENTS > sizeof_field(TranslationBlock, trace_vcpu_dstate) @@ -1170,339 +1153,6 @@ void cpu_interrupt(CPUState *cpu, int mask) qatomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1); } -/* - * Walks guest process memory "regions" one by one - * and calls callback function 'fn' for each region. - */ -struct walk_memory_regions_data { - walk_memory_regions_fn fn; - void *priv; - target_ulong start; - int prot; -}; - -static int walk_memory_regions_end(struct walk_memory_regions_data *data, - target_ulong end, int new_prot) -{ - if (data->start != -1u) { - int rc = data->fn(data->priv, data->start, end, data->prot); - if (rc != 0) { - return rc; - } - } - - data->start = (new_prot ? end : -1u); - data->prot = new_prot; - - return 0; -} - -static int walk_memory_regions_1(struct walk_memory_regions_data *data, - target_ulong base, int level, void **lp) -{ - target_ulong pa; - int i, rc; - - if (*lp == NULL) { - return walk_memory_regions_end(data, base, 0); - } - - if (level == 0) { - PageDesc *pd = *lp; - - for (i = 0; i < V_L2_SIZE; ++i) { - int prot = pd[i].flags; - - pa = base | (i << TARGET_PAGE_BITS); - if (prot != data->prot) { - rc = walk_memory_regions_end(data, pa, prot); - if (rc != 0) { - return rc; - } - } - } - } else { - void **pp = *lp; - - for (i = 0; i < V_L2_SIZE; ++i) { - pa = base | ((target_ulong)i << - (TARGET_PAGE_BITS + V_L2_BITS * level)); - rc = walk_memory_regions_1(data, pa, level - 1, pp + i); - if (rc != 0) { - return rc; - } - } - } - - return 0; -} - -int walk_memory_regions(void *priv, walk_memory_regions_fn fn) -{ - struct walk_memory_regions_data data; - uintptr_t i, l1_sz = v_l1_size; - - data.fn = fn; - data.priv = priv; - data.start = -1u; - data.prot = 0; - - for (i = 0; i < l1_sz; i++) { - target_ulong base = i << (v_l1_shift + TARGET_PAGE_BITS); - int rc = walk_memory_regions_1(&data, base, v_l2_levels, l1_map + i); - if (rc != 0) { - return rc; - } - } - - return walk_memory_regions_end(&data, 0, 0); -} - -static int dump_region(void *priv, target_ulong start, - target_ulong end, unsigned long prot) -{ - FILE *f = (FILE *)priv; - - (void) fprintf(f, TARGET_FMT_lx"-"TARGET_FMT_lx - " "TARGET_FMT_lx" %c%c%c\n", - start, end, end - start, - ((prot & PAGE_READ) ? 'r' : '-'), - ((prot & PAGE_WRITE) ? 'w' : '-'), - ((prot & PAGE_EXEC) ? 'x' : '-')); - - return 0; -} - -/* dump memory mappings */ -void page_dump(FILE *f) -{ - const int length = sizeof(target_ulong) * 2; - (void) fprintf(f, "%-*s %-*s %-*s %s\n", - length, "start", length, "end", length, "size", "prot"); - walk_memory_regions(f, dump_region); -} - -int page_get_flags(target_ulong address) -{ - PageDesc *p; - - p = page_find(address >> TARGET_PAGE_BITS); - if (!p) { - return 0; - } - return p->flags; -} - -/* - * Allow the target to decide if PAGE_TARGET_[12] may be reset. - * By default, they are not kept. - */ -#ifndef PAGE_TARGET_STICKY -#define PAGE_TARGET_STICKY 0 -#endif -#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 - on PAGE_WRITE. The mmap_lock should already be held. */ -void page_set_flags(target_ulong start, target_ulong end, int flags) -{ - target_ulong addr, len; - bool reset, inval_tb = false; - - /* This function should never be called with addresses outside the - guest address space. If this assert fires, it probably indicates - a missing call to h2g_valid. */ - assert(end - 1 <= GUEST_ADDR_MAX); - assert(start < end); - /* Only set PAGE_ANON with new mappings. */ - assert(!(flags & PAGE_ANON) || (flags & PAGE_RESET)); - assert_memory_lock(); - - start = start & TARGET_PAGE_MASK; - end = TARGET_PAGE_ALIGN(end); - - if (flags & PAGE_WRITE) { - flags |= PAGE_WRITE_ORG; - } - reset = !(flags & PAGE_VALID) || (flags & PAGE_RESET); - if (reset) { - page_reset_target_data(start, end); - } - flags &= ~PAGE_RESET; - - for (addr = start, len = end - start; - len != 0; - len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) { - PageDesc *p = page_find_alloc(addr >> TARGET_PAGE_BITS, true); - - /* - * If the page was executable, but is reset, or is no longer - * executable, or has become writable, then invalidate any code. - */ - if ((p->flags & PAGE_EXEC) - && (reset || - !(flags & PAGE_EXEC) || - (flags & ~p->flags & PAGE_WRITE))) { - inval_tb = true; - } - /* Using mprotect on a page does not change sticky bits. */ - p->flags = (reset ? 0 : p->flags & PAGE_STICKY) | flags; - } - - if (inval_tb) { - tb_invalidate_phys_range(start, end); - } -} - -int page_check_range(target_ulong start, target_ulong len, int flags) -{ - PageDesc *p; - target_ulong end; - target_ulong addr; - - /* This function should never be called with addresses outside the - guest address space. If this assert fires, it probably indicates - a missing call to h2g_valid. */ - if (TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS) { - assert(start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)); - } - - if (len == 0) { - return 0; - } - if (start + len - 1 < start) { - /* We've wrapped around. */ - return -1; - } - - /* must do before we loose bits in the next step */ - end = TARGET_PAGE_ALIGN(start + len); - start = start & TARGET_PAGE_MASK; - - for (addr = start, len = end - start; - len != 0; - len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) { - p = page_find(addr >> TARGET_PAGE_BITS); - if (!p) { - return -1; - } - if (!(p->flags & PAGE_VALID)) { - return -1; - } - - if ((flags & PAGE_READ) && !(p->flags & PAGE_READ)) { - return -1; - } - if (flags & PAGE_WRITE) { - if (!(p->flags & PAGE_WRITE_ORG)) { - return -1; - } - /* unprotect the page if it was put read-only because it - contains translated code */ - if (!(p->flags & PAGE_WRITE)) { - if (!page_unprotect(addr, 0)) { - return -1; - } - } - } - } - return 0; -} - -void page_protect(tb_page_addr_t page_addr) -{ - target_ulong addr; - PageDesc *p; - int prot; - - p = page_find(page_addr >> TARGET_PAGE_BITS); - if (p && (p->flags & PAGE_WRITE)) { - /* - * Force the host page as non writable (writes will have a page fault + - * mprotect overhead). - */ - page_addr &= qemu_host_page_mask; - prot = 0; - for (addr = page_addr; addr < page_addr + qemu_host_page_size; - addr += TARGET_PAGE_SIZE) { - - p = page_find(addr >> TARGET_PAGE_BITS); - if (!p) { - continue; - } - prot |= p->flags; - p->flags &= ~PAGE_WRITE; - } - mprotect(g2h_untagged(page_addr), qemu_host_page_size, - (prot & PAGE_BITS) & ~PAGE_WRITE); - } -} - -/* called from signal handler: invalidate the code and unprotect the - * page. Return 0 if the fault was not handled, 1 if it was handled, - * and 2 if it was handled but the caller must cause the TB to be - * immediately exited. (We can only return 2 if the 'pc' argument is - * non-zero.) - */ -int page_unprotect(target_ulong address, uintptr_t pc) -{ - unsigned int prot; - bool current_tb_invalidated; - PageDesc *p; - target_ulong host_start, host_end, addr; - - /* Technically this isn't safe inside a signal handler. However we - know this only ever happens in a synchronous SEGV handler, so in - practice it seems to be ok. */ - mmap_lock(); - - p = page_find(address >> TARGET_PAGE_BITS); - if (!p) { - mmap_unlock(); - return 0; - } - - /* if the page was really writable, then we change its - protection back to writable */ - if (p->flags & PAGE_WRITE_ORG) { - current_tb_invalidated = false; - if (p->flags & PAGE_WRITE) { - /* If the page is actually marked WRITE then assume this is because - * this thread raced with another one which got here first and - * set the page to PAGE_WRITE and did the TB invalidate for us. - */ -#ifdef TARGET_HAS_PRECISE_SMC - TranslationBlock *current_tb = tcg_tb_lookup(pc); - if (current_tb) { - current_tb_invalidated = tb_cflags(current_tb) & CF_INVALID; - } -#endif - } else { - host_start = address & qemu_host_page_mask; - host_end = host_start + qemu_host_page_size; - - prot = 0; - for (addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE) { - p = page_find(addr >> TARGET_PAGE_BITS); - p->flags |= PAGE_WRITE; - prot |= p->flags; - - /* and since the content will be modified, we must invalidate - the corresponding translated code. */ - current_tb_invalidated |= - tb_invalidate_phys_page_unwind(addr, pc); - } - mprotect((void *)g2h_untagged(host_start), qemu_host_page_size, - prot & PAGE_BITS); - } - mmap_unlock(); - /* If current TB was invalidated return to main loop */ - return current_tb_invalidated ? 2 : 1; - } - mmap_unlock(); - return 0; -} #endif /* CONFIG_USER_ONLY */ /* diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c index 42a04bd..22ef780 100644 --- a/accel/tcg/user-exec.c +++ b/accel/tcg/user-exec.c @@ -135,6 +135,352 @@ bool handle_sigsegv_accerr_write(CPUState *cpu, sigset_t *old_set, } } +/* + * Walks guest process memory "regions" one by one + * and calls callback function 'fn' for each region. + */ +struct walk_memory_regions_data { + walk_memory_regions_fn fn; + void *priv; + target_ulong start; + int prot; +}; + +static int walk_memory_regions_end(struct walk_memory_regions_data *data, + target_ulong end, int new_prot) +{ + if (data->start != -1u) { + int rc = data->fn(data->priv, data->start, end, data->prot); + if (rc != 0) { + return rc; + } + } + + data->start = (new_prot ? end : -1u); + data->prot = new_prot; + + return 0; +} + +static int walk_memory_regions_1(struct walk_memory_regions_data *data, + target_ulong base, int level, void **lp) +{ + target_ulong pa; + int i, rc; + + if (*lp == NULL) { + return walk_memory_regions_end(data, base, 0); + } + + if (level == 0) { + PageDesc *pd = *lp; + + for (i = 0; i < V_L2_SIZE; ++i) { + int prot = pd[i].flags; + + pa = base | (i << TARGET_PAGE_BITS); + if (prot != data->prot) { + rc = walk_memory_regions_end(data, pa, prot); + if (rc != 0) { + return rc; + } + } + } + } else { + void **pp = *lp; + + for (i = 0; i < V_L2_SIZE; ++i) { + pa = base | ((target_ulong)i << + (TARGET_PAGE_BITS + V_L2_BITS * level)); + rc = walk_memory_regions_1(data, pa, level - 1, pp + i); + if (rc != 0) { + return rc; + } + } + } + + return 0; +} + +int walk_memory_regions(void *priv, walk_memory_regions_fn fn) +{ + struct walk_memory_regions_data data; + uintptr_t i, l1_sz = v_l1_size; + + data.fn = fn; + data.priv = priv; + data.start = -1u; + data.prot = 0; + + for (i = 0; i < l1_sz; i++) { + target_ulong base = i << (v_l1_shift + TARGET_PAGE_BITS); + int rc = walk_memory_regions_1(&data, base, v_l2_levels, l1_map + i); + if (rc != 0) { + return rc; + } + } + + return walk_memory_regions_end(&data, 0, 0); +} + +static int dump_region(void *priv, target_ulong start, + target_ulong end, unsigned long prot) +{ + FILE *f = (FILE *)priv; + + (void) fprintf(f, TARGET_FMT_lx"-"TARGET_FMT_lx + " "TARGET_FMT_lx" %c%c%c\n", + start, end, end - start, + ((prot & PAGE_READ) ? 'r' : '-'), + ((prot & PAGE_WRITE) ? 'w' : '-'), + ((prot & PAGE_EXEC) ? 'x' : '-')); + + return 0; +} + +/* dump memory mappings */ +void page_dump(FILE *f) +{ + const int length = sizeof(target_ulong) * 2; + (void) fprintf(f, "%-*s %-*s %-*s %s\n", + length, "start", length, "end", length, "size", "prot"); + walk_memory_regions(f, dump_region); +} + +int page_get_flags(target_ulong address) +{ + PageDesc *p; + + p = page_find(address >> TARGET_PAGE_BITS); + if (!p) { + return 0; + } + return p->flags; +} + +/* + * Allow the target to decide if PAGE_TARGET_[12] may be reset. + * By default, they are not kept. + */ +#ifndef PAGE_TARGET_STICKY +#define PAGE_TARGET_STICKY 0 +#endif +#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 + * on PAGE_WRITE. The mmap_lock should already be held. + */ +void page_set_flags(target_ulong start, target_ulong end, int flags) +{ + target_ulong addr, len; + bool reset, inval_tb = false; + + /* This function should never be called with addresses outside the + guest address space. If this assert fires, it probably indicates + a missing call to h2g_valid. */ + assert(end - 1 <= GUEST_ADDR_MAX); + assert(start < end); + /* Only set PAGE_ANON with new mappings. */ + assert(!(flags & PAGE_ANON) || (flags & PAGE_RESET)); + assert_memory_lock(); + + start = start & TARGET_PAGE_MASK; + end = TARGET_PAGE_ALIGN(end); + + if (flags & PAGE_WRITE) { + flags |= PAGE_WRITE_ORG; + } + reset = !(flags & PAGE_VALID) || (flags & PAGE_RESET); + if (reset) { + page_reset_target_data(start, end); + } + flags &= ~PAGE_RESET; + + for (addr = start, len = end - start; + len != 0; + len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) { + PageDesc *p = page_find_alloc(addr >> TARGET_PAGE_BITS, true); + + /* + * If the page was executable, but is reset, or is no longer + * executable, or has become writable, then invalidate any code. + */ + if ((p->flags & PAGE_EXEC) + && (reset || + !(flags & PAGE_EXEC) || + (flags & ~p->flags & PAGE_WRITE))) { + inval_tb = true; + } + /* Using mprotect on a page does not change sticky bits. */ + p->flags = (reset ? 0 : p->flags & PAGE_STICKY) | flags; + } + + if (inval_tb) { + tb_invalidate_phys_range(start, end); + } +} + +int page_check_range(target_ulong start, target_ulong len, int flags) +{ + PageDesc *p; + target_ulong end; + target_ulong addr; + + /* + * This function should never be called with addresses outside the + * guest address space. If this assert fires, it probably indicates + * a missing call to h2g_valid. + */ + if (TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS) { + assert(start < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS)); + } + + if (len == 0) { + return 0; + } + if (start + len - 1 < start) { + /* We've wrapped around. */ + return -1; + } + + /* must do before we loose bits in the next step */ + end = TARGET_PAGE_ALIGN(start + len); + start = start & TARGET_PAGE_MASK; + + for (addr = start, len = end - start; + len != 0; + len -= TARGET_PAGE_SIZE, addr += TARGET_PAGE_SIZE) { + p = page_find(addr >> TARGET_PAGE_BITS); + if (!p) { + return -1; + } + if (!(p->flags & PAGE_VALID)) { + return -1; + } + + if ((flags & PAGE_READ) && !(p->flags & PAGE_READ)) { + return -1; + } + if (flags & PAGE_WRITE) { + if (!(p->flags & PAGE_WRITE_ORG)) { + return -1; + } + /* unprotect the page if it was put read-only because it + contains translated code */ + if (!(p->flags & PAGE_WRITE)) { + if (!page_unprotect(addr, 0)) { + return -1; + } + } + } + } + return 0; +} + +void page_protect(tb_page_addr_t page_addr) +{ + target_ulong addr; + PageDesc *p; + int prot; + + p = page_find(page_addr >> TARGET_PAGE_BITS); + if (p && (p->flags & PAGE_WRITE)) { + /* + * Force the host page as non writable (writes will have a page fault + + * mprotect overhead). + */ + page_addr &= qemu_host_page_mask; + prot = 0; + for (addr = page_addr; addr < page_addr + qemu_host_page_size; + addr += TARGET_PAGE_SIZE) { + + p = page_find(addr >> TARGET_PAGE_BITS); + if (!p) { + continue; + } + prot |= p->flags; + p->flags &= ~PAGE_WRITE; + } + mprotect(g2h_untagged(page_addr), qemu_host_page_size, + (prot & PAGE_BITS) & ~PAGE_WRITE); + } +} + +/* + * Called from signal handler: invalidate the code and unprotect the + * page. Return 0 if the fault was not handled, 1 if it was handled, + * and 2 if it was handled but the caller must cause the TB to be + * immediately exited. (We can only return 2 if the 'pc' argument is + * non-zero.) + */ +int page_unprotect(target_ulong address, uintptr_t pc) +{ + unsigned int prot; + bool current_tb_invalidated; + PageDesc *p; + target_ulong host_start, host_end, addr; + + /* + * Technically this isn't safe inside a signal handler. However we + * know this only ever happens in a synchronous SEGV handler, so in + * practice it seems to be ok. + */ + mmap_lock(); + + p = page_find(address >> TARGET_PAGE_BITS); + if (!p) { + mmap_unlock(); + return 0; + } + + /* + * If the page was really writable, then we change its + * protection back to writable. + */ + if (p->flags & PAGE_WRITE_ORG) { + current_tb_invalidated = false; + if (p->flags & PAGE_WRITE) { + /* + * If the page is actually marked WRITE then assume this is because + * this thread raced with another one which got here first and + * set the page to PAGE_WRITE and did the TB invalidate for us. + */ +#ifdef TARGET_HAS_PRECISE_SMC + TranslationBlock *current_tb = tcg_tb_lookup(pc); + if (current_tb) { + current_tb_invalidated = tb_cflags(current_tb) & CF_INVALID; + } +#endif + } else { + host_start = address & qemu_host_page_mask; + host_end = host_start + qemu_host_page_size; + + prot = 0; + for (addr = host_start; addr < host_end; addr += TARGET_PAGE_SIZE) { + p = page_find(addr >> TARGET_PAGE_BITS); + p->flags |= PAGE_WRITE; + prot |= p->flags; + + /* + * Since the content will be modified, we must invalidate + * the corresponding translated code. + */ + current_tb_invalidated |= + tb_invalidate_phys_page_unwind(addr, pc); + } + mprotect((void *)g2h_untagged(host_start), qemu_host_page_size, + prot & PAGE_BITS); + } + mmap_unlock(); + /* If current TB was invalidated return to main loop */ + return current_tb_invalidated ? 2 : 1; + } + mmap_unlock(); + return 0; +} + static int probe_access_internal(CPUArchState *env, target_ulong addr, int fault_size, MMUAccessType access_type, bool nonfault, uintptr_t ra) |