From 18238ae670fb38f5ca7002bc8da7b7aa9d612f68 Mon Sep 17 00:00:00 2001 From: Laszlo Ersek Date: Sat, 11 Jan 2014 17:59:58 +0100 Subject: [PATCH 08/22] pc_sysfw: allow flash (-pflash) memory to be used with KVM RH-Author: Laszlo Ersek Message-id: <1389463208-6278-9-git-send-email-lersek@redhat.com> Patchwork-id: 56621 O-Subject: [RHEL-7.0 qemu-kvm PATCH 08/18] pc_sysfw: allow flash (-pflash) memory to be used with KVM Bugzilla: 1032346 RH-Acked-by: Paolo Bonzini RH-Acked-by: Amos Kong RH-Acked-by: Andrew Jones From: 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 KVM_CAP_READONLY_MEM, 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 Reviewed-by: Paolo Bonzini Message-id: 1369816047-16384-5-git-send-email-jordan.l.justen@intel.com Signed-off-by: Anthony Liguori (cherry picked from commit dafb82e0fc89b631d25f8def649fbfd14fec3db2) Signed-off-by: Laszlo Ersek --- hw/block/pc_sysfw.c | 50 +++++++++++++++++++++++++++++++------------------- 1 file changed, 31 insertions(+), 19 deletions(-) Signed-off-by: Miroslav Rezanina --- hw/block/pc_sysfw.c | 50 +++++++++++++++++++++++++++++++------------------- 1 files changed, 31 insertions(+), 19 deletions(-) diff --git a/hw/block/pc_sysfw.c b/hw/block/pc_sysfw.c index 4d82c70..76932fc 100644 --- a/hw/block/pc_sysfw.c +++ b/hw/block/pc_sysfw.c @@ -217,28 +217,40 @@ 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, sysfw_dev->isapc_ram_fw); - 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. Let's fix it for real in QEMU 1.6. - */ - if (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, sysfw_dev->isapc_ram_fw); - 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, sysfw_dev->isapc_ram_fw); + return; } /* If a pflash drive is not found, then create one using -- 1.7.1