From patchwork Thu Jan 12 18:24:14 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Laszlo Ersek X-Patchwork-Id: 9513895 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C1C20601E5 for ; Thu, 12 Jan 2017 18:25:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B76872870A for ; Thu, 12 Jan 2017 18:25:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AAEC12870D; Thu, 12 Jan 2017 18:25:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 3BFCA2870A for ; Thu, 12 Jan 2017 18:25:16 +0000 (UTC) Received: from localhost ([::1]:35953 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cRk3n-00012q-88 for patchwork-qemu-devel@patchwork.kernel.org; Thu, 12 Jan 2017 13:25:15 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47968) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cRk3C-0000yP-05 for qemu-devel@nongnu.org; Thu, 12 Jan 2017 13:24:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cRk39-0002LV-EJ for qemu-devel@nongnu.org; Thu, 12 Jan 2017 13:24:37 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43946) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cRk33-0002Jo-U5; Thu, 12 Jan 2017 13:24:30 -0500 Received: from smtp.corp.redhat.com (int-mx16.intmail.prod.int.phx2.redhat.com [10.5.11.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 156A2C04B302; Thu, 12 Jan 2017 18:24:30 +0000 (UTC) Received: from lacos-laptop-7.usersys.redhat.com (ovpn-116-42.phx2.redhat.com [10.3.116.42]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7C709685DB; Thu, 12 Jan 2017 18:24:27 +0000 (UTC) From: Laszlo Ersek To: qemu devel list Date: Thu, 12 Jan 2017 19:24:14 +0100 Message-Id: <20170112182417.9548-2-lersek@redhat.com> In-Reply-To: <20170112182417.9548-1-lersek@redhat.com> References: <20170112182417.9548-1-lersek@redhat.com> X-Scanned-By: MIMEDefang 2.74 on 10.5.11.28 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Thu, 12 Jan 2017 18:24:30 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v6 wave 1 1/4] fw-cfg: support writeable blobs X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , "Michael S. Tsirkin" , "Gabriel L. Somlo" , Shannon Zhao , Michael Walle , qemu-arm@nongnu.org, Gerd Hoffmann , Paolo Bonzini , Igor Mammedov Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP From: "Michael S. Tsirkin" Useful to send guest data back to QEMU. Changes from Laszlo Ersek : - rebase the patch from Michael Tsirkin's original postings at [1] and [2] to the following patches: - loader: Allow a custom AddressSpace when loading ROMs - loader: Add AddressSpace loading support to uImages - loader: fix handling of custom address spaces when adding ROM blobs - reject such writes immediately that would exceed the end of the array, rather than performing a partial write before setting the error bit: see the (len != dma.length) condition - document the write interface [1] http://lists.nongnu.org/archive/html/qemu-devel/2016-02/msg04968.html [2] http://lists.nongnu.org/archive/html/qemu-devel/2016-03/msg02735.html Cc: "Gabriel L. Somlo" Cc: "Michael S. Tsirkin" Cc: Gerd Hoffmann Cc: Igor Mammedov Cc: Michael Walle Cc: Paolo Bonzini Cc: Peter Maydell Cc: Shannon Zhao Cc: qemu-arm@nongnu.org Signed-off-by: Michael S. Tsirkin Signed-off-by: Laszlo Ersek Reviewed-by: Marcel Apfelbaum Acked-by: Gabriel Somlo Tested-by: Gabriel Somlo --- Notes: v6: - no changes, pick up Gabriel's A-b and T-b v5: - no changes, just picked up Marcel's R-b docs/specs/fw_cfg.txt | 32 +++++++++++++++++++++++++------- hw/lm32/lm32_hwsetup.h | 2 +- include/hw/loader.h | 7 ++++--- include/hw/nvram/fw_cfg.h | 3 ++- hw/arm/virt-acpi-build.c | 2 +- hw/core/loader.c | 18 +++++++++++------- hw/i386/acpi-build.c | 4 ++-- hw/nvram/fw_cfg.c | 37 +++++++++++++++++++++++++++++-------- 8 files changed, 75 insertions(+), 30 deletions(-) diff --git a/docs/specs/fw_cfg.txt b/docs/specs/fw_cfg.txt index 7a5f8c7824ce..a19e2adbe1c6 100644 --- a/docs/specs/fw_cfg.txt +++ b/docs/specs/fw_cfg.txt @@ -33,6 +33,10 @@ the selector value is between 0x4000-0x7fff or 0xc000-0xffff. NOTE: As of QEMU v2.4, writes to the fw_cfg data register are no longer supported, and will be ignored (treated as no-ops)! +NOTE: As of QEMU v2.9, writes are reinstated, but only through the DMA + interface (see below). Furthermore, writeability of any specific item is + governed independently of Bit14 in the selector key value. + Bit15 of the selector register indicates whether the configuration setting is architecture specific. A value of 0 means the item is a generic configuration item. A value of 1 means the item is specific @@ -43,7 +47,7 @@ value between 0x8000-0xffff. == Data Register == -* Read/Write (writes ignored as of QEMU v2.4) +* Read/Write (writes ignored as of QEMU v2.4, but see the DMA interface) * Location: platform dependent (IOport [*] or MMIO) * Width: 8-bit (if IOport), 8/16/32/64-bit (if MMIO) * Endianness: string-preserving @@ -134,8 +138,8 @@ struct FWCfgFile { /* an individual file entry, 64 bytes total */ === All Other Data Items === -Please consult the QEMU source for the most up-to-date and authoritative -list of selector keys and their respective items' purpose and format. +Please consult the QEMU source for the most up-to-date and authoritative list +of selector keys and their respective items' purpose, format and writeability. === Ranges === @@ -144,9 +148,11 @@ items, and up to 0x4000 architecturally specific ones. Selector Reg. Range Usage --------------- ----------- -0x0000 - 0x3fff Generic (0x0000 - 0x3fff, RO) +0x0000 - 0x3fff Generic (0x0000 - 0x3fff, generally RO, possibly RW through + the DMA interface in QEMU v2.9+) 0x4000 - 0x7fff Generic (0x0000 - 0x3fff, RW, ignored in QEMU v2.4+) -0x8000 - 0xbfff Arch. Specific (0x0000 - 0x3fff, RO) +0x8000 - 0xbfff Arch. Specific (0x0000 - 0x3fff, generally RO, possibly RW + through the DMA interface in QEMU v2.9+) 0xc000 - 0xffff Arch. Specific (0x0000 - 0x3fff, RW, ignored in v2.4+) In practice, the number of allowed firmware configuration items is given @@ -182,6 +188,7 @@ The "control" field has the following bits: - Bit 1: Read - Bit 2: Skip - Bit 3: Select. The upper 16 bits are the selected index. + - Bit 4: Write When an operation is triggered, if the "control" field has bit 3 set, the upper 16 bits are interpreted as an index of a firmware configuration item. @@ -191,8 +198,17 @@ If the "control" field has bit 1 set, a read operation will be performed. "length" bytes for the current selector and offset will be copied into the physical RAM address specified by the "address" field. -If the "control" field has bit 2 set (and not bit 1), a skip operation will be -performed. The offset for the current selector will be advanced "length" bytes. +If the "control" field has bit 4 set (and not bit 1), a write operation will be +performed. "length" bytes will be copied from the physical RAM address +specified by the "address" field to the current selector and offset. QEMU +prevents starting or finishing the write beyond the end of the item associated +with the current selector (i.e., the item cannot be resized). Truncated writes +are dropped entirely. Writes to read-only items are also rejected. All of these +write errors set bit 0 (the error bit) in the "control" field. + +If the "control" field has bit 2 set (and neither bit 1 nor bit 4), a skip +operation will be performed. The offset for the current selector will be +advanced "length" bytes. To check the result, read the "control" field: error bit set -> something went wrong. @@ -234,3 +250,5 @@ Prefix "opt/org.qemu/" is reserved for QEMU itself. Use of names not beginning with "opt/" is potentially dangerous and entirely unsupported. QEMU will warn if you try. + +All externally provided fw_cfg items are read-only to the guest. diff --git a/hw/lm32/lm32_hwsetup.h b/hw/lm32/lm32_hwsetup.h index 23e18784dffd..a01f6bc5dfeb 100644 --- a/hw/lm32/lm32_hwsetup.h +++ b/hw/lm32/lm32_hwsetup.h @@ -75,7 +75,7 @@ static inline void hwsetup_create_rom(HWSetup *hw, hwaddr base) { rom_add_blob("hwsetup", hw->data, TARGET_PAGE_SIZE, - TARGET_PAGE_SIZE, base, NULL, NULL, NULL, NULL); + TARGET_PAGE_SIZE, base, NULL, NULL, NULL, NULL, true); } static inline void hwsetup_add_u8(HWSetup *hw, uint8_t u) diff --git a/include/hw/loader.h b/include/hw/loader.h index 0c864cfd6046..0dbd8d6bf37a 100644 --- a/include/hw/loader.h +++ b/include/hw/loader.h @@ -180,7 +180,8 @@ MemoryRegion *rom_add_blob(const char *name, const void *blob, size_t len, size_t max_len, hwaddr addr, const char *fw_file_name, FWCfgReadCallback fw_callback, - void *callback_opaque, AddressSpace *as); + void *callback_opaque, AddressSpace *as, + bool read_only); int rom_add_elf_program(const char *name, void *data, size_t datasize, size_t romsize, hwaddr addr, AddressSpace *as); int rom_check_and_register_reset(void); @@ -194,7 +195,7 @@ void hmp_info_roms(Monitor *mon, const QDict *qdict); #define rom_add_file_fixed(_f, _a, _i) \ rom_add_file(_f, NULL, _a, _i, false, NULL, NULL) #define rom_add_blob_fixed(_f, _b, _l, _a) \ - rom_add_blob(_f, _b, _l, _l, _a, NULL, NULL, NULL, NULL) + rom_add_blob(_f, _b, _l, _l, _a, NULL, NULL, NULL, NULL, true) #define rom_add_file_mr(_f, _mr, _i) \ rom_add_file(_f, NULL, 0, _i, false, _mr, NULL) #define rom_add_file_as(_f, _as, _i) \ @@ -202,7 +203,7 @@ void hmp_info_roms(Monitor *mon, const QDict *qdict); #define rom_add_file_fixed_as(_f, _a, _i, _as) \ rom_add_file(_f, NULL, _a, _i, false, NULL, _as) #define rom_add_blob_fixed_as(_f, _b, _l, _a, _as) \ - rom_add_blob(_f, _b, _l, _l, _a, NULL, NULL, NULL, _as) + rom_add_blob(_f, _b, _l, _l, _a, NULL, NULL, NULL, _as, true) #define PC_ROM_MIN_VGA 0xc0000 #define PC_ROM_MIN_OPTION 0xc8000 diff --git a/include/hw/nvram/fw_cfg.h b/include/hw/nvram/fw_cfg.h index 5c27a1f0d50b..b980cbaebf43 100644 --- a/include/hw/nvram/fw_cfg.h +++ b/include/hw/nvram/fw_cfg.h @@ -136,6 +136,7 @@ void fw_cfg_add_file(FWCfgState *s, const char *filename, void *data, * @callback_opaque: argument to be passed into callback function * @data: pointer to start of item data * @len: size of item data + * @read_only: is file read only * * Add a new NAMED fw_cfg item as a raw "blob" of the given size. The data * referenced by the starting pointer is only linked, NOT copied, into the @@ -151,7 +152,7 @@ void fw_cfg_add_file(FWCfgState *s, const char *filename, void *data, */ void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, FWCfgReadCallback callback, void *callback_opaque, - void *data, size_t len); + void *data, size_t len, bool read_only); /** * fw_cfg_modify_file: diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c index 085a61117378..205d6268e217 100644 --- a/hw/arm/virt-acpi-build.c +++ b/hw/arm/virt-acpi-build.c @@ -818,7 +818,7 @@ static MemoryRegion *acpi_add_rom_blob(AcpiBuildState *build_state, uint64_t max_size) { return rom_add_blob(name, blob->data, acpi_data_len(blob), max_size, -1, - name, virt_acpi_build_update, build_state, NULL); + name, virt_acpi_build_update, build_state, NULL, true); } static const VMStateDescription vmstate_virt_acpi_build = { diff --git a/hw/core/loader.c b/hw/core/loader.c index 45742494e6fd..ee5abd6eb7f4 100644 --- a/hw/core/loader.c +++ b/hw/core/loader.c @@ -853,7 +853,7 @@ static void fw_cfg_resized(const char *id, uint64_t length, void *host) } } -static void *rom_set_mr(Rom *rom, Object *owner, const char *name) +static void *rom_set_mr(Rom *rom, Object *owner, const char *name, bool ro) { void *data; @@ -862,7 +862,7 @@ static void *rom_set_mr(Rom *rom, Object *owner, const char *name) rom->datasize, rom->romsize, fw_cfg_resized, &error_fatal); - memory_region_set_readonly(rom->mr, true); + memory_region_set_readonly(rom->mr, ro); vmstate_register_ram_global(rom->mr); data = memory_region_get_ram_ptr(rom->mr); @@ -942,7 +942,7 @@ int rom_add_file(const char *file, const char *fw_dir, snprintf(devpath, sizeof(devpath), "/rom@%s", fw_file_name); if ((!option_rom || mc->option_rom_has_mr) && mc->rom_file_has_mr) { - data = rom_set_mr(rom, OBJECT(fw_cfg), devpath); + data = rom_set_mr(rom, OBJECT(fw_cfg), devpath, true); } else { data = rom->data; } @@ -979,7 +979,7 @@ err: MemoryRegion *rom_add_blob(const char *name, const void *blob, size_t len, size_t max_len, hwaddr addr, const char *fw_file_name, FWCfgReadCallback fw_callback, void *callback_opaque, - AddressSpace *as) + AddressSpace *as, bool read_only) { MachineClass *mc = MACHINE_GET_CLASS(qdev_get_machine()); Rom *rom; @@ -998,10 +998,14 @@ MemoryRegion *rom_add_blob(const char *name, const void *blob, size_t len, char devpath[100]; void *data; - snprintf(devpath, sizeof(devpath), "/rom@%s", fw_file_name); + if (read_only) { + snprintf(devpath, sizeof(devpath), "/rom@%s", fw_file_name); + } else { + snprintf(devpath, sizeof(devpath), "/ram@%s", fw_file_name); + } if (mc->rom_file_has_mr) { - data = rom_set_mr(rom, OBJECT(fw_cfg), devpath); + data = rom_set_mr(rom, OBJECT(fw_cfg), devpath, read_only); mr = rom->mr; } else { data = rom->data; @@ -1009,7 +1013,7 @@ MemoryRegion *rom_add_blob(const char *name, const void *blob, size_t len, fw_cfg_add_file_callback(fw_cfg, fw_file_name, fw_callback, callback_opaque, - data, rom->datasize); + data, rom->datasize, read_only); } return mr; } diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 0c8912fd861b..a1d781ae42d8 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -2806,7 +2806,7 @@ static MemoryRegion *acpi_add_rom_blob(AcpiBuildState *build_state, uint64_t max_size) { return rom_add_blob(name, blob->data, acpi_data_len(blob), max_size, -1, - name, acpi_build_update, build_state, NULL); + name, acpi_build_update, build_state, NULL, true); } static const VMStateDescription vmstate_acpi_build = { @@ -2872,7 +2872,7 @@ void acpi_setup(void) build_state->rsdp = g_memdup(tables.rsdp->data, rsdp_size); fw_cfg_add_file_callback(pcms->fw_cfg, ACPI_BUILD_RSDP_FILE, acpi_build_update, build_state, - build_state->rsdp, rsdp_size); + build_state->rsdp, rsdp_size, true); build_state->rsdp_mr = NULL; } else { build_state->rsdp = NULL; diff --git a/hw/nvram/fw_cfg.c b/hw/nvram/fw_cfg.c index 3ebecb22606a..e0145c11a19b 100644 --- a/hw/nvram/fw_cfg.c +++ b/hw/nvram/fw_cfg.c @@ -54,11 +54,13 @@ #define FW_CFG_DMA_CTL_READ 0x02 #define FW_CFG_DMA_CTL_SKIP 0x04 #define FW_CFG_DMA_CTL_SELECT 0x08 +#define FW_CFG_DMA_CTL_WRITE 0x10 #define FW_CFG_DMA_SIGNATURE 0x51454d5520434647ULL /* "QEMU CFG" */ typedef struct FWCfgEntry { uint32_t len; + bool allow_write; uint8_t *data; void *callback_opaque; FWCfgReadCallback read_callback; @@ -326,7 +328,7 @@ static void fw_cfg_dma_transfer(FWCfgState *s) FWCfgDmaAccess dma; int arch; FWCfgEntry *e; - int read; + int read = 0, write = 0; dma_addr_t dma_addr; /* Reset the address before the next access */ @@ -353,8 +355,13 @@ static void fw_cfg_dma_transfer(FWCfgState *s) if (dma.control & FW_CFG_DMA_CTL_READ) { read = 1; + write = 0; + } else if (dma.control & FW_CFG_DMA_CTL_WRITE) { + read = 0; + write = 1; } else if (dma.control & FW_CFG_DMA_CTL_SKIP) { read = 0; + write = 0; } else { dma.length = 0; } @@ -374,7 +381,9 @@ static void fw_cfg_dma_transfer(FWCfgState *s) dma.control |= FW_CFG_DMA_CTL_ERROR; } } - + if (write) { + dma.control |= FW_CFG_DMA_CTL_ERROR; + } } else { if (dma.length <= (e->len - s->cur_offset)) { len = dma.length; @@ -391,6 +400,14 @@ static void fw_cfg_dma_transfer(FWCfgState *s) dma.control |= FW_CFG_DMA_CTL_ERROR; } } + if (write) { + if (!e->allow_write || + len != dma.length || + dma_memory_read(s->dma_as, dma.address, + &e->data[s->cur_offset], len)) { + dma.control |= FW_CFG_DMA_CTL_ERROR; + } + } s->cur_offset += len; } @@ -586,7 +603,8 @@ static const VMStateDescription vmstate_fw_cfg = { static void fw_cfg_add_bytes_read_callback(FWCfgState *s, uint16_t key, FWCfgReadCallback callback, void *callback_opaque, - void *data, size_t len) + void *data, size_t len, + bool read_only) { int arch = !!(key & FW_CFG_ARCH_LOCAL); @@ -599,6 +617,7 @@ static void fw_cfg_add_bytes_read_callback(FWCfgState *s, uint16_t key, s->entries[arch][key].len = (uint32_t)len; s->entries[arch][key].read_callback = callback; s->entries[arch][key].callback_opaque = callback_opaque; + s->entries[arch][key].allow_write = !read_only; } static void *fw_cfg_modify_bytes_read(FWCfgState *s, uint16_t key, @@ -616,13 +635,14 @@ static void *fw_cfg_modify_bytes_read(FWCfgState *s, uint16_t key, s->entries[arch][key].data = data; s->entries[arch][key].len = len; s->entries[arch][key].callback_opaque = NULL; + s->entries[arch][key].allow_write = false; return ptr; } void fw_cfg_add_bytes(FWCfgState *s, uint16_t key, void *data, size_t len) { - fw_cfg_add_bytes_read_callback(s, key, NULL, NULL, data, len); + fw_cfg_add_bytes_read_callback(s, key, NULL, NULL, data, len, true); } void fw_cfg_add_string(FWCfgState *s, uint16_t key, const char *value) @@ -749,7 +769,7 @@ static int get_fw_cfg_order(FWCfgState *s, const char *name) void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, FWCfgReadCallback callback, void *callback_opaque, - void *data, size_t len) + void *data, size_t len, bool read_only) { int i, index, count; size_t dsize; @@ -811,7 +831,8 @@ void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, } fw_cfg_add_bytes_read_callback(s, FW_CFG_FILE_FIRST + index, - callback, callback_opaque, data, len); + callback, callback_opaque, data, len, + read_only); s->files->f[index].size = cpu_to_be32(len); s->files->f[index].select = cpu_to_be16(FW_CFG_FILE_FIRST + index); @@ -824,7 +845,7 @@ void fw_cfg_add_file_callback(FWCfgState *s, const char *filename, void fw_cfg_add_file(FWCfgState *s, const char *filename, void *data, size_t len) { - fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len); + fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len, true); } void *fw_cfg_modify_file(FWCfgState *s, const char *filename, @@ -847,7 +868,7 @@ void *fw_cfg_modify_file(FWCfgState *s, const char *filename, } } /* add new one */ - fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len); + fw_cfg_add_file_callback(s, filename, NULL, NULL, data, len, true); return NULL; }