From 9665f41979eafa554fd6f20aa5d300460ab833df Mon Sep 17 00:00:00 2001 From: implicitfield <114500360+implicitfield@users.noreply.github.com> Date: Tue, 6 Dec 2022 23:47:45 +0200 Subject: Kernel: Ignore an invalid QEMU multiboot entry This was introduced in the QEMU commit 8504f12 and was causing the kernel to fail to boot on the q35 machine. Fixes #14952. --- Kernel/Memory/MemoryManager.cpp | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) (limited to 'Kernel/Memory') diff --git a/Kernel/Memory/MemoryManager.cpp b/Kernel/Memory/MemoryManager.cpp index 25ebf1f048..5537bba12b 100644 --- a/Kernel/Memory/MemoryManager.cpp +++ b/Kernel/Memory/MemoryManager.cpp @@ -291,7 +291,18 @@ UNMAP_AFTER_INIT void MemoryManager::parse_memory_map() global_data.physical_memory_ranges.append(PhysicalMemoryRange { PhysicalMemoryRangeType::Usable, start_address, length }); break; case (MULTIBOOT_MEMORY_RESERVED): - global_data.physical_memory_ranges.append(PhysicalMemoryRange { PhysicalMemoryRangeType::Reserved, start_address, length }); +#if ARCH(I386) || ARCH(X86_64) + // Workaround for https://gitlab.com/qemu-project/qemu/-/commit/8504f129450b909c88e199ca44facd35d38ba4de + // That commit added a reserved 12GiB entry for the benefit of virtual firmware. + // We can safely ignore this block as it isn't actually reserved on any real hardware. + // From: https://lore.kernel.org/all/20220701161014.3850-1-joao.m.martins@oracle.com/ + // "Always add the HyperTransport range into e820 even when the relocation isn't + // done *and* there's >= 40 phys bit that would put max phyusical boundary to 1T + // This should allow virtual firmware to avoid the reserved range at the + // 1T boundary on VFs with big bars." + if (address != 0x000000fd00000000 || length != (0x000000ffffffffff - 0x000000fd00000000) + 1) +#endif + global_data.physical_memory_ranges.append(PhysicalMemoryRange { PhysicalMemoryRangeType::Reserved, start_address, length }); break; case (MULTIBOOT_MEMORY_ACPI_RECLAIMABLE): global_data.physical_memory_ranges.append(PhysicalMemoryRange { PhysicalMemoryRangeType::ACPI_Reclaimable, start_address, length }); -- cgit v1.2.3