Paolo Bonzini <pbonz...@redhat.com> writes:
> The variable is not written anymore.
This cleans up after 9e1c2ec (which accidentally left variable
pc_sysfw_flash_vs_rom_bug_compatible behind, value always zero), and
buries dead code from commit dafb82e (which looks like it got confused
by pc_sysfw_flash_vs_rom_bug_compatible). Suggest to mention that in
the commit message.
Hunk from dafb82e in question:
- /* 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;
}
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
> ---
> hw/block/pc_sysfw.c | 26 +-------------------------
> 1 file changed, 1 insertion(+), 25 deletions(-)
>
> diff --git a/hw/block/pc_sysfw.c b/hw/block/pc_sysfw.c
> index 412d1b0..c6d4be4 100644
> --- a/hw/block/pc_sysfw.c
> +++ b/hw/block/pc_sysfw.c
> @@ -199,12 +199,6 @@ static void old_pc_system_rom_init(MemoryRegion
> *rom_memory, bool isapc_ram_fw)
> bios);
> }
>
> -/*
> - * Bug-compatible flash vs. ROM selection enabled?
> - * A few older machines enable this.
> - */
> -bool pc_sysfw_flash_vs_rom_bug_compatible;
> -
> void pc_system_firmware_init(MemoryRegion *rom_memory)
> {
> DriveInfo *pflash_drv;
> @@ -222,25 +216,7 @@ void pc_system_firmware_init(MemoryRegion *rom_memory)
>
> pflash_drv = drive_get(IF_PFLASH, 0, 0);
>
> - 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) {
> + 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()) {
