From patchwork Mon Jul 19 10:16:12 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Richard W.M. Jones" X-Patchwork-Id: 59189 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [199.232.76.165]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id A07931007D6 for ; Mon, 19 Jul 2010 20:21:43 +1000 (EST) Received: from localhost ([127.0.0.1]:57765 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OanTg-00038Q-Ly for incoming@patchwork.ozlabs.org; Mon, 19 Jul 2010 06:21:40 -0400 Received: from [140.186.70.92] (port=37474 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OanOS-0000q2-Jk for qemu-devel@nongnu.org; Mon, 19 Jul 2010 06:16:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OanOR-0000hU-0e for qemu-devel@nongnu.org; Mon, 19 Jul 2010 06:16:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:9684) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OanOQ-0000gK-Ko for qemu-devel@nongnu.org; Mon, 19 Jul 2010 06:16:14 -0400 Received: from int-mx03.intmail.prod.int.phx2.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.16]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o6JAGEdH024174 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 19 Jul 2010 06:16:14 -0400 Received: from localhost (vpn1-5-94.ams2.redhat.com [10.36.5.94]) by int-mx03.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o6JAGDgh019698 for ; Mon, 19 Jul 2010 06:16:13 -0400 Date: Mon, 19 Jul 2010 11:16:12 +0100 From: "Richard W.M. Jones" To: qemu-devel@nongnu.org Message-ID: <20100719101612.GC5216@amd.home.annexia.org> References: <20100717133930.GC19767@amd.home.annexia.org> <20100719101504.GA5216@amd.home.annexia.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20100719101504.GA5216@amd.home.annexia.org> User-Agent: Mutt/1.5.18 (2008-05-17) X-Scanned-By: MIMEDefang 2.67 on 10.5.11.16 X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. Subject: [Qemu-devel] [PATCH 2/2 version 2] fw_cfg: Allow guest to read kernel etc via fast, synchronous "DMA"-type operation. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org diff --git a/hw/fw_cfg.c b/hw/fw_cfg.c index 37e6f1f..798a332 100644 --- a/hw/fw_cfg.c +++ b/hw/fw_cfg.c @@ -55,6 +55,13 @@ struct FWCfgState { uint32_t cur_offset; }; +/* Target address and size for DMA operations. This is only used + * during boot and across 32 and 64 bit architectures, so only writes + * to lower 4GB addresses are supported. + */ +static uint32_t dma_addr = 0; +static uint32_t dma_size = 0; + static void fw_cfg_write(FWCfgState *s, uint8_t value) { int arch = !!(s->cur_entry & FW_CFG_ARCH_LOCAL); @@ -98,7 +105,16 @@ static uint8_t fw_cfg_read(FWCfgState *s) if (s->cur_entry == FW_CFG_INVALID || !e->data || s->cur_offset >= e->len) ret = 0; - else + else if (s->cur_entry & FW_CFG_DMA) { + if (dma_size > e->len - s->cur_offset) + dma_size = e->len - s->cur_offset; + + cpu_physical_memory_write ((target_phys_addr_t) dma_addr, + &e->data[s->cur_offset], + dma_size); + s->cur_offset += e->len; + ret = 1; + } else ret = e->data[s->cur_offset++]; FW_CFG_DPRINTF("read %d\n", ret); @@ -351,6 +367,10 @@ FWCfgState *fw_cfg_init(uint32_t ctl_port, uint32_t data_port, fw_cfg_add_i16(s, FW_CFG_NB_CPUS, (uint16_t)smp_cpus); fw_cfg_add_i16(s, FW_CFG_MAX_CPUS, (uint16_t)max_cpus); fw_cfg_add_i16(s, FW_CFG_BOOT_MENU, (uint16_t)boot_menu); + fw_cfg_add_bytes(s, FW_CFG_DMA_ADDR | FW_CFG_WRITE_CHANNEL, + (uint8_t *)&dma_addr, sizeof dma_addr); + fw_cfg_add_bytes(s, FW_CFG_DMA_SIZE | FW_CFG_WRITE_CHANNEL, + (uint8_t *)&dma_size, sizeof dma_size); return s; } diff --git a/hw/fw_cfg.h b/hw/fw_cfg.h index 4d13a4f..44b2be5 100644 --- a/hw/fw_cfg.h +++ b/hw/fw_cfg.h @@ -30,11 +30,15 @@ #define FW_CFG_FILE_FIRST 0x20 #define FW_CFG_FILE_SLOTS 0x10 -#define FW_CFG_MAX_ENTRY (FW_CFG_FILE_FIRST+FW_CFG_FILE_SLOTS) +#define FW_CFG_DMA_ADDR 0x30 +#define FW_CFG_DMA_SIZE 0x31 +#define FW_CFG_MAX_ENTRY (FW_CFG_DMA_SIZE+1) + +#define FW_CFG_DMA 0x2000 #define FW_CFG_WRITE_CHANNEL 0x4000 #define FW_CFG_ARCH_LOCAL 0x8000 -#define FW_CFG_ENTRY_MASK ~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL) +#define FW_CFG_ENTRY_MASK ~(FW_CFG_DMA | FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL) #define FW_CFG_INVALID 0xffff diff --git a/pc-bios/optionrom/linuxboot.S b/pc-bios/optionrom/linuxboot.S index c109363..dbf44cb 100644 --- a/pc-bios/optionrom/linuxboot.S +++ b/pc-bios/optionrom/linuxboot.S @@ -106,10 +106,10 @@ copy_kernel: /* We're now running in 16-bit CS, but 32-bit ES! */ /* Load kernel and initrd */ - read_fw_blob_addr32(FW_CFG_KERNEL) - read_fw_blob_addr32(FW_CFG_INITRD) - read_fw_blob_addr32(FW_CFG_CMDLINE) - read_fw_blob_addr32(FW_CFG_SETUP) + read_fw_blob_dma(FW_CFG_KERNEL) + read_fw_blob_dma(FW_CFG_INITRD) + read_fw_blob_dma(FW_CFG_CMDLINE) + read_fw_blob_dma(FW_CFG_SETUP) /* And now jump into Linux! */ mov $0, %eax diff --git a/pc-bios/optionrom/optionrom.h b/pc-bios/optionrom/optionrom.h index fbdd48a..7fffe2d 100644 --- a/pc-bios/optionrom/optionrom.h +++ b/pc-bios/optionrom/optionrom.h @@ -50,6 +50,27 @@ bswap %eax .endm +/* + * Write %eax to a variable in the fw_cfg device. + * In: %eax + * Clobbers: %edx + */ +.macro write_fw VAR + push %eax + mov $(\VAR|FW_CFG_WRITE_CHANNEL), %ax + mov $BIOS_CFG_IOPORT_CFG, %dx + outw %ax, (%dx) + pop %eax + mov $BIOS_CFG_IOPORT_DATA, %dx + outb %al, (%dx) + shr $8, %eax + outb %al, (%dx) + shr $8, %eax + outb %al, (%dx) + shr $8, %eax + outb %al, (%dx) +.endm + #define read_fw_blob_pre(var) \ read_fw var ## _ADDR; \ mov %eax, %edi; \ @@ -87,6 +108,22 @@ */ \ .dc.b 0x67,0xf3,0x6c +/* + * Fast DMA of data from fw_cfg device into physical memory. + * This should be a straight replacement for read_fw_blob and + * read_fw_blob_addr32. + */ +#define read_fw_blob_dma(var) \ + read_fw var ## _ADDR; \ + write_fw FW_CFG_DMA_ADDR; \ + read_fw var ## _SIZE; \ + write_fw FW_CFG_DMA_SIZE; \ + mov $(var ## _DATA|FW_CFG_DMA), %ax; \ + mov $BIOS_CFG_IOPORT_CFG, %edx; \ + outw %ax, (%dx); \ + mov $BIOS_CFG_IOPORT_DATA, %dx; \ + inb (%dx), %al + #define OPTION_ROM_START \ .code16; \ .text; \