xen/arch/x86/acpi/boot.c | 8 ++ xen/arch/x86/efi/efi-boot.h | 5 ++ xen/common/efi/boot.c | 158 ++++++++++++++++++++++++++++++++++++ xen/include/xen/efi.h | 1 + 4 files changed, 172 insertions(+)
This RFC series plans to addres ACPI BGRT (Boot Graphics Resource Table) corruption, that occured when Xen reuses the memory containing the boot logo image before dom0 is able to parse ACPI tables. The BGRT table contains a pointer to a BMP image stored in BootServicesData memory. When Xen reclaims this memory early in boot, the pointer becomes invalid, causing Linux dom0 to report: Xen: `(XEN) ACPI: BGRT: invalidating v1 image at 0x47cc2018` Linux (dom0): `ACPI BIOS Warning (bug): Incorrect checksum in table [BGRT] - 0xF9, should be 0xB4 (20250807/utcksum-58)` This series: 1. Adds BGRT image preservation infrastructure during EFI boot (validates BMP format, allocates EfiACPIReclaimMemory, stores pointers) 2. Integrates preservation with ACPI subsystem (clarifies acpi_invalidate_bgrt() safety net behavior, adds status reporting via efi_bgrt_status_info()) 3. Provides opt-out mechanism (-nobgrt for xen.efi direct boot, efi=no-bgrt for multiboot2, both via early EFI-phase parsing) The preservation is enabled by default to fix the corruption for all users, with minimal overhead (~1MB). Also, servers that don't need boot graphics can disable it using the "efi=no-bgrt" option. Thank you everyone for the constructive feedback! It is really helpful, I hope this RFC series is upto standards, I would greatly appriciate further feedback. Changes since v1: - The BGRT invalidation behaviour should still presist and server as a safety net when "efi=no-bgrt" or the preservation fails for some reason thus: Add Clarify comment for BGRT invalidation behavior with preservation. Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Changes since v2: - Use existing ACPI headers (actbl.h, actbl3.h) instead of custom structs - Modify the function names and code in function to conform with Coding Style. - Reuse efi.acpi20 from efi_tables() instead of manual RSDP search - Use appropriate types: EFI types for firmware code, unsigned int for loop counters (matching ESRT pattern) - Used of sizeof(<expression>) over sizeof(<type>) - Remove fixed-type widths & limited typecasting - Add Blank line ahead of the main return statement of a function. - Better wording error message for image cap size - Remove parse_boolean(no-bgrt) since it could be bit misleading - Add const qualifiers throughout for safety - Use %p format for pointers (32-bit compatibility) - Initialize failure_reason with string literal for proper relocation - Use memcmp() with ACPI_SIG_* constants for signature checks - Add direct Xen.efi calling. - Add opt-out mechanism with proper early parsing during EFI phase. Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Reported-by: Jan Beulich <jbeulich@suse.com> Please refer to QubesOS Issue for more context: https://github.com/QubesOS/qubes-issues/issues/10764 This is a companion series to Linux Kernel side at https://patchew.org/linux/cover.751f45ebbb644244b1d9da3aff289d6b66db4c6b.1773058629.git-series.marmarek@invisiblethingslab.com/ Testing: - Verified on Intel UEFI system with Fedora 43 dom0 - Before: ACPI checksum errors in dom0 - After: Clean boot, no ACPI warnings - Memory overhead: ~972 KB (preserved image size) Signed-off-by: Soumyajyotii Ssarkar <soumyajyotisarkar23@gmail.com> Soumyajyotii Ssarkar (3): x86/efi: Add BGRT image preservation infrastructure x86/acpi: Integrate BGRT preservation with status reporting x86/efi: Add opt-out mechanism for BGRT preservation xen/arch/x86/acpi/boot.c | 8 ++ xen/arch/x86/efi/efi-boot.h | 5 ++ xen/common/efi/boot.c | 158 ++++++++++++++++++++++++++++++++++++ xen/include/xen/efi.h | 1 + 4 files changed, 172 insertions(+) -- 2.53.0
On Thu, Mar 12, 2026 at 04:44:11PM +0530, Soumyajyotii Ssarkar wrote: > This RFC series plans to addres ACPI BGRT (Boot Graphics Resource Table) corruption, > that occured when Xen reuses the memory containing the boot logo > image before dom0 is able to parse ACPI tables. > > The BGRT table contains a pointer to a BMP image stored in > BootServicesData memory. When Xen reclaims this memory early in boot, > the pointer becomes invalid, causing Linux dom0 to report: > Xen: `(XEN) ACPI: BGRT: invalidating v1 image at 0x47cc2018` > Linux (dom0): `ACPI BIOS Warning (bug): Incorrect checksum > in table [BGRT] - 0xF9, should be 0xB4 (20250807/utcksum-58)` > > This series: > 1. Adds BGRT image preservation infrastructure during EFI boot > (validates BMP format, allocates EfiACPIReclaimMemory, stores pointers) > > 2. Integrates preservation with ACPI subsystem > (clarifies acpi_invalidate_bgrt() safety net behavior, > adds status reporting via efi_bgrt_status_info()) > > 3. Provides opt-out mechanism > (-nobgrt for xen.efi direct boot, efi=no-bgrt > for multiboot2, both via early EFI-phase parsing) > > The preservation is enabled by default to fix the corruption for all > users, with minimal overhead (~1MB). Also, servers that don't need boot > graphics can disable it using the "efi=no-bgrt" option. > > Thank you everyone for the constructive feedback! It is really helpful, > I hope this RFC series is upto standards, I would greatly appriciate further feedback. > > Changes since v1: > - The BGRT invalidation behaviour should still presist > and server as a safety net when "efi=no-bgrt" or the > preservation fails for some reason thus: Add Clarify comment > for BGRT invalidation behavior with preservation. > Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > > Changes since v2: > - Use existing ACPI headers (actbl.h, actbl3.h) instead of custom structs > - Modify the function names and code in function to conform with Coding Style. > - Reuse efi.acpi20 from efi_tables() instead of manual RSDP search > - Use appropriate types: EFI types for firmware code, unsigned int for > loop counters (matching ESRT pattern) > - Used of sizeof(<expression>) over sizeof(<type>) > - Remove fixed-type widths & limited typecasting > - Add Blank line ahead of the main return statement of a function. > - Better wording error message for image cap size > - Remove parse_boolean(no-bgrt) since it could be bit misleading > - Add const qualifiers throughout for safety > - Use %p format for pointers (32-bit compatibility) > - Initialize failure_reason with string literal for proper relocation > - Use memcmp() with ACPI_SIG_* constants for signature checks > - Add direct Xen.efi calling. > - Add opt-out mechanism with proper early parsing during EFI phase. > > Reported-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> > Reported-by: Jan Beulich <jbeulich@suse.com> > > Please refer to QubesOS Issue for more context: > https://github.com/QubesOS/qubes-issues/issues/10764 > > This is a companion series to Linux Kernel side at > https://patchew.org/linux/cover.751f45ebbb644244b1d9da3aff289d6b66db4c6b.1773058629.git-series.marmarek@invisiblethingslab.com/ > > Testing: > - Verified on Intel UEFI system with Fedora 43 dom0 > - Before: ACPI checksum errors in dom0 > - After: Clean boot, no ACPI warnings > - Memory overhead: ~972 KB (preserved image size) > > Signed-off-by: Soumyajyotii Ssarkar <soumyajyotisarkar23@gmail.com> Hi, I've pushed this series to CI, and it fails to build in several targets: https://gitlab.com/xen-project/people/marmarek/xen/-/pipelines/2390562809 -- Best Regards, Marek Marczykowski-Górecki Invisible Things Lab
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