From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:40149) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UXR2g-0002wE-7h for qemu-devel@nongnu.org; Wed, 01 May 2013 03:01:34 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UXR2c-0003ir-0q for qemu-devel@nongnu.org; Wed, 01 May 2013 03:01:30 -0400 Received: from mga14.intel.com ([143.182.124.37]:60313) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UXR2b-0003i3-Pt for qemu-devel@nongnu.org; Wed, 01 May 2013 03:01:25 -0400 From: Jordan Justen Date: Tue, 30 Apr 2013 23:56:32 -0700 Message-Id: <1367391393-6830-6-git-send-email-jordan.l.justen@intel.com> In-Reply-To: <1367391393-6830-1-git-send-email-jordan.l.justen@intel.com> References: <1367391393-6830-1-git-send-email-jordan.l.justen@intel.com> Subject: [Qemu-devel] [PATCH v2 5/6] pc_sysfw: allow flash (-pflash) memory to be used with KVM List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Jordan Justen When pc-sysfw.rom_only != 0, flash memory will be usable with kvm. In order to enable flash memory mode, a pflash device must be created. (For example, by using the -pflash command line parameter.) Usage of a flash memory device with kvm requires the KVM READONLY memory capability, and kvm will abort if a flash device is used with an older kvm which does not support this capability. If a flash device is not used, then qemu/kvm will operate in the original rom-mode. Signed-off-by: Jordan Justen --- hw/block/pc_sysfw.c | 50 +++++++++++++++++++++++++++++++------------------- 1 file changed, 31 insertions(+), 19 deletions(-) diff --git a/hw/block/pc_sysfw.c b/hw/block/pc_sysfw.c index aad8614..301eb96 100644 --- a/hw/block/pc_sysfw.c +++ b/hw/block/pc_sysfw.c @@ -215,28 +215,40 @@ void pc_system_firmware_init(MemoryRegion *rom_memory) qdev_init_nofail(DEVICE(sysfw_dev)); - if (sysfw_dev->rom_only) { - old_pc_system_rom_init(rom_memory); - return; - } - pflash_drv = drive_get(IF_PFLASH, 0, 0); - /* Currently KVM cannot execute from device memory. - Use old rom based firmware initialization for KVM. */ - /* - * This is a Bad Idea, because it makes enabling/disabling KVM - * guest-visible. Do it only in bug-compatibility mode. - */ - if (pc_sysfw_flash_vs_rom_bug_compatible && kvm_enabled()) { - if (pflash_drv != NULL) { - fprintf(stderr, "qemu: pflash cannot be used with kvm enabled\n"); - exit(1); - } else { - sysfw_dev->rom_only = 1; - old_pc_system_rom_init(rom_memory); - return; + if (pc_sysfw_flash_vs_rom_bug_compatible) { + /* + * This is a Bad Idea, because it makes enabling/disabling KVM + * guest-visible. Do it only in bug-compatibility mode. + */ + if (kvm_enabled()) { + if (pflash_drv != NULL) { + fprintf(stderr, "qemu: pflash cannot be used with kvm enabled\n"); + exit(1); + } else { + /* In old pc_sysfw_flash_vs_rom_bug_compatible mode, we assume + * that KVM cannot execute from device memory. In this case, we + * use old rom based firmware initialization for KVM. But, since + * this is different from non-kvm mode, this behavior is + * undesirable */ + sysfw_dev->rom_only = 1; + } } + } else if (pflash_drv == NULL) { + /* When a pflash drive is not found, use rom-mode */ + sysfw_dev->rom_only = 1; + } else if (kvm_enabled() && !kvm_readonly_mem_enabled()) { + /* Older KVM cannot execute from device memory. So, flash memory + * cannot be used unless the readonly memory kvm capability is present. */ + fprintf(stderr, "qemu: pflash with kvm requires KVM readonly memory support\n"); + exit(1); + } + + /* If rom-mode is active, use the old pc system rom initialization. */ + if (sysfw_dev->rom_only) { + old_pc_system_rom_init(rom_memory); + return; } /* If a pflash drive is not found, then create one using -- 1.7.10.4