From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1NnhKD-0005bY-VB for qemu-devel@nongnu.org; Fri, 05 Mar 2010 18:52:57 -0500 Received: from [199.232.76.173] (port=45220 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1NnhKD-0005b9-MO for qemu-devel@nongnu.org; Fri, 05 Mar 2010 18:52:57 -0500 Received: from Debian-exim by monty-python.gnu.org with spam-scanned (Exim 4.60) (envelope-from ) id 1NnhKB-0001OU-V9 for qemu-devel@nongnu.org; Fri, 05 Mar 2010 18:52:57 -0500 Received: from fleet.cs.ualberta.ca ([129.128.22.22]:50882) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1NnhKB-0001Ns-Dv for qemu-devel@nongnu.org; Fri, 05 Mar 2010 18:52:55 -0500 From: Cam Macdonell Date: Fri, 5 Mar 2010 16:52:40 -0700 Message-Id: <1267833161-25267-1-git-send-email-cam@cs.ualberta.ca> Subject: [Qemu-devel] [PATCH] Support adding a file to qemu's ram allocation List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Cam Macdonell , kvm@vger.kernel.org This avoids the need of using qemu_ram_alloc and mmap with MAP_FIXED to map a host file into guest RAM. This function mmaps the opened file anywhere and adds the memory to the ram blocks. Usage is qemu_add_file_to_ram(fd, size, MAP_SHARED); --- cpu-common.h | 1 + exec.c | 33 +++++++++++++++++++++++++++++++++ 2 files changed, 34 insertions(+), 0 deletions(-) diff --git a/cpu-common.h b/cpu-common.h index 326513d..2d95079 100644 --- a/cpu-common.h +++ b/cpu-common.h @@ -30,6 +30,7 @@ static inline void cpu_register_physical_memory(target_phys_addr_t start_addr, } ram_addr_t cpu_get_physical_page_desc(target_phys_addr_t addr); +ram_addr_t qemu_add_file_to_ram(int, ram_addr_t, int); ram_addr_t qemu_ram_alloc(ram_addr_t); void qemu_ram_free(ram_addr_t addr); /* This should only be used for ram local to a device. */ diff --git a/exec.c b/exec.c index 69003c2..955adee 100644 --- a/exec.c +++ b/exec.c @@ -2623,6 +2623,39 @@ static void *file_ram_alloc(ram_addr_t memory, const char *path) extern const char *mem_path; +ram_addr_t qemu_add_file_to_ram(int fd, ram_addr_t size, int flags) +{ + RAMBlock *new_block; + + size = TARGET_PAGE_ALIGN(size); + new_block = qemu_malloc(sizeof(*new_block)); + + // map the file passed as a parameter to be this part of memory + new_block->host = mmap(0, size, PROT_READ|PROT_WRITE, flags, fd, 0); + +#ifdef MADV_MERGEABLE + madvise(new_block->host, size, MADV_MERGEABLE); +#endif + + new_block->offset = last_ram_offset; + new_block->length = size; + + new_block->next = ram_blocks; + ram_blocks = new_block; + + phys_ram_dirty = qemu_realloc(phys_ram_dirty, + (last_ram_offset + size) >> TARGET_PAGE_BITS); + memset(phys_ram_dirty + (last_ram_offset >> TARGET_PAGE_BITS), + 0xff, size >> TARGET_PAGE_BITS); + + last_ram_offset += size; + + if (kvm_enabled()) + kvm_setup_guest_memory(new_block->host, size); + + return new_block->offset; +} + ram_addr_t qemu_ram_alloc(ram_addr_t size) { RAMBlock *new_block; -- 1.6.0.6