Am 27. Januar 2026 05:15:39 UTC schrieb Ani Sinha <[email protected]>:
>For confidential guests, bios image must be reinitialized upon reset. This
>is because bios memory is encrypted and hence once the old confidential
>kvm context is destroyed, it cannot be decrypted. It needs to be reinitilized.
>In order to do that, this change refactors x86_bios_rom_init() code so that
>parts of it can be called during confidential guest reset.
>
>Signed-off-by: Ani Sinha <[email protected]>
>---
> hw/i386/x86-common.c | 51 ++++++++++++++++++++++++++++++++-----------
> include/hw/i386/x86.h | 1 -
> 2 files changed, 38 insertions(+), 14 deletions(-)
>
>diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c
>index c1c9224039..4469b4e152 100644
>--- a/hw/i386/x86-common.c
>+++ b/hw/i386/x86-common.c
>@@ -1024,17 +1024,11 @@ void x86_isa_bios_init(MemoryRegion *isa_bios,
>MemoryRegion *isa_memory,
> memory_region_set_readonly(isa_bios, read_only);
> }
>
>-void x86_bios_rom_init(X86MachineState *x86ms, const char *default_firmware,
>- MemoryRegion *rom_memory, bool isapc_ram_fw)
>+static int get_bios_size(X86MachineState *x86ms,
>+ const char *bios_name, char *filename)
> {
>- const char *bios_name;
>- char *filename;
> int bios_size;
>- ssize_t ret;
>
>- /* BIOS load */
>- bios_name = MACHINE(x86ms)->firmware ?: default_firmware;
>- filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
> if (filename) {
> bios_size = get_image_size(filename, NULL);
> } else {
>@@ -1044,6 +1038,21 @@ void x86_bios_rom_init(X86MachineState *x86ms, const
>char *default_firmware,
> (bios_size % 65536) != 0) {
> goto bios_error;
> }
>+
>+ return bios_size;
>+
>+ bios_error:
>+ fprintf(stderr, "qemu: could not load PC BIOS '%s'\n", bios_name);
>+ exit(1);
>+}
>+
>+static void load_bios_from_file(X86MachineState *x86ms, const char *bios_name,
>+ char *filename, int bios_size,
>+ bool isapc_ram_fw)
>+{
>+ ssize_t ret;
>+
>+ /* BIOS load */
> if (machine_require_guest_memfd(MACHINE(x86ms))) {
> memory_region_init_ram_guest_memfd(&x86ms->bios, NULL, "pc.bios",
> bios_size, &error_fatal);
>@@ -1072,7 +1081,26 @@ void x86_bios_rom_init(X86MachineState *x86ms, const
>char *default_firmware,
> goto bios_error;
> }
> }
>- g_free(filename);
>+
>+ return;
>+
>+ bios_error:
>+ fprintf(stderr, "qemu: could not load PC BIOS '%s'\n", bios_name);
>+ exit(1);
>+}
>+
>+void x86_bios_rom_init(X86MachineState *x86ms, const char *default_firmware,
>+ MemoryRegion *rom_memory, bool isapc_ram_fw)
>+{
>+ int bios_size;
>+ const char *bios_name;
>+ char *filename;
>+
>+ bios_name = MACHINE(x86ms)->firmware ?: default_firmware;
>+ filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, bios_name);
>+
>+ bios_size = get_bios_size(x86ms, bios_name, filename);
>+ load_bios_from_file(x86ms, bios_name, filename, bios_size, isapc_ram_fw);
>
> if (!machine_require_guest_memfd(MACHINE(x86ms))) {
> /* map the last 128KB of the BIOS in ISA space */
>@@ -1084,9 +1112,6 @@ void x86_bios_rom_init(X86MachineState *x86ms, const
>char *default_firmware,
> memory_region_add_subregion(rom_memory,
> (uint32_t)(-bios_size),
> &x86ms->bios);
>+ g_free(filename);
Doesn't the error path leak filename? Using g_autofree would prevent that. Even
if the error path exits immediately today it may represent a latent bug for
tomorrow (e.g. when porting to error API).
> return;
>-
>-bios_error:
>- fprintf(stderr, "qemu: could not load PC BIOS '%s'\n", bios_name);
>- exit(1);
> }
>diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h
>index 0dffba95f9..bfdf97640d 100644
>--- a/include/hw/i386/x86.h
>+++ b/include/hw/i386/x86.h
>@@ -122,7 +122,6 @@ void x86_cpu_unplug_request_cb(HotplugHandler *hotplug_dev,
> DeviceState *dev, Error **errp);
> void x86_cpu_unplug_cb(HotplugHandler *hotplug_dev,
> DeviceState *dev, Error **errp);
>-
This file contains whitespace changes only and breaks logic grouping of
functions. I'd drop this change.
Best regards,
Bernhard
> void x86_isa_bios_init(MemoryRegion *isa_bios, MemoryRegion *isa_memory,
> MemoryRegion *bios, bool read_only);
> void x86_bios_rom_init(X86MachineState *x86ms, const char *default_firmware,
