From cd571b76520f1b0b63f82b272fa084d352508094 Mon Sep 17 00:00:00 2001 From: Dean Nelson Date: Mon, 11 Jul 2011 00:28:27 -0300 Subject: [RHEL6 qemu-kvm PATCH 4/6] Add qemu_ram_remap RH-Author: Dean Nelson Message-id: <20110711002826.2936.43909.email-sent-by-dnelson@localhost6.localdomain6> Patchwork-id: 29378 O-Subject: [RHEL6.2 qemu-kvm PATCH 4/6 v2] Add qemu_ram_remap Bugzilla: 696102 RH-Acked-by: Jes Sorensen RH-Acked-by: Alex Williamson RH-Acked-by: Marcelo Tosatti Resolves RHBZ 696102 v2 - Ensure disable_KSM is not true before doing the MADV_MERGEABLE madvise() call in qemu_ram_remap(). Backport of: commit cd19cfa23609dc1a35dd34f0b7554a8462337fde Author: Huang Ying Date: Wed Mar 2 08:56:19 2011 +0100 Add qemu_ram_remap qemu_ram_remap() unmaps the specified RAM pages, then re-maps these pages again. This is used by KVM HWPoison support to clear HWPoisoned page tables across guest rebooting, so that a new page may be allocated later to recover the memory error. [ Jan: style fixlets, WIN32 fix ] Signed-off-by: Huang Ying Signed-off-by: Jan Kiszka Signed-off-by: Marcelo Tosatti --- cpu-all.h | 4 +++ cpu-common.h | 1 + exec.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 71 insertions(+), 2 deletions(-) Signed-off-by: Eduardo Habkost --- cpu-all.h | 4 +++ cpu-common.h | 1 + exec.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 71 insertions(+), 2 deletions(-) diff --git a/cpu-all.h b/cpu-all.h index 939627f..334de68 100644 --- a/cpu-all.h +++ b/cpu-all.h @@ -849,10 +849,14 @@ extern int phys_ram_fd; extern ram_addr_t ram_size; extern uint8_t *bios_mem; +/* RAM is pre-allocated and passed into qemu_ram_alloc_from_ptr */ +#define RAM_PREALLOC_MASK (1 << 0) + typedef struct RAMBlock { uint8_t *host; ram_addr_t offset; ram_addr_t length; + uint32_t flags; char idstr[256]; QLIST_ENTRY(RAMBlock) next; #if defined(__linux__) && !defined(TARGET_S390X) diff --git a/cpu-common.h b/cpu-common.h index b9ae398..8f1d8e4 100644 --- a/cpu-common.h +++ b/cpu-common.h @@ -34,6 +34,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, ram_addr_t size, void *host); ram_addr_t qemu_ram_alloc(DeviceState *dev, const char *name, ram_addr_t size); void qemu_ram_free(ram_addr_t addr); +void qemu_ram_remap(ram_addr_t addr, ram_addr_t length); /* This should only be used for ram local to a device. */ void *qemu_get_ram_ptr(ram_addr_t addr); /* This should not be used by devices. */ diff --git a/exec.c b/exec.c index 6f02b02..751fd60 100644 --- a/exec.c +++ b/exec.c @@ -2637,6 +2637,7 @@ static void *file_ram_alloc(ram_addr_t memory, const char *path) #endif extern const char *mem_path; +extern int disable_KSM; #if defined(__linux__) && defined(__x86_64__) /* @@ -2691,7 +2692,6 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, ram_addr_t size, void *host) { RAMBlock *new_block, *block; - extern int disable_KSM; size = TARGET_PAGE_ALIGN(size); new_block = qemu_mallocz(sizeof(*new_block)); @@ -2715,6 +2715,7 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, if (host) { new_block->host = host; + new_block->flags |= RAM_PREALLOC_MASK; } else { new_block->host = file_ram_alloc(new_block, size, mem_path); if (!new_block->host) { @@ -2783,7 +2784,9 @@ void qemu_ram_free(ram_addr_t addr) QLIST_FOREACH(block, &ram_list.blocks, next) { if (addr == block->offset) { QLIST_REMOVE(block, next); - if (mem_path) { + if (block->flags & RAM_PREALLOC_MASK) { + ; + } else if (mem_path) { #if defined (__linux__) && !defined(TARGET_S390X) if (block->fd) { munmap(block->host, block->length); @@ -2806,6 +2809,67 @@ void qemu_ram_free(ram_addr_t addr) } +#ifndef _WIN32 +void qemu_ram_remap(ram_addr_t addr, ram_addr_t length) +{ + RAMBlock *block; + ram_addr_t offset; + int flags; + void *area, *vaddr; + + QLIST_FOREACH(block, &ram_list.blocks, next) { + offset = addr - block->offset; + if (offset < block->length) { + vaddr = block->host + offset; + if (block->flags & RAM_PREALLOC_MASK) { + ; + } else { + flags = MAP_FIXED; + munmap(vaddr, length); + if (mem_path) { +#if defined(__linux__) && !defined(TARGET_S390X) + if (block->fd) { +#ifdef MAP_POPULATE + flags |= mem_prealloc ? MAP_POPULATE | MAP_SHARED : + MAP_PRIVATE; +#else + flags |= MAP_PRIVATE; +#endif + area = mmap(vaddr, length, PROT_READ | PROT_WRITE, + flags, block->fd, offset); + } else { + flags |= MAP_PRIVATE | MAP_ANONYMOUS; + area = mmap(vaddr, length, PROT_READ | PROT_WRITE, + flags, -1, 0); + } +#endif + } else { +#if defined(TARGET_S390X) && defined(CONFIG_KVM) + flags |= MAP_SHARED | MAP_ANONYMOUS; + area = mmap(vaddr, length, PROT_EXEC|PROT_READ|PROT_WRITE, + flags, -1, 0); +#else + flags |= MAP_PRIVATE | MAP_ANONYMOUS; + area = mmap(vaddr, length, PROT_READ | PROT_WRITE, + flags, -1, 0); +#endif + } + if (area != vaddr) { + fprintf(stderr, "Could not remap addr: %lx@%lx\n", + length, addr); + exit(1); + } +#ifdef MADV_MERGEABLE + if (!disable_KSM) + madvise(vaddr, length, MADV_MERGEABLE); +#endif + } + return; + } + } +} +#endif /* !_WIN32 */ + /* Return a host pointer to ram allocated with qemu_ram_alloc. With the exception of the softmmu code in this file, this should only be used for local memory (e.g. video ram) that the device owns, -- 1.7.3.2