From fc7a69e177e4ba26d11fcf47b853f85115b35a11 Mon Sep 17 00:00:00 2001 From: Michael Roth Date: Thu, 30 May 2024 06:16:40 -0500 Subject: hw/i386: Add support for loading BIOS using guest_memfd When guest_memfd is enabled, the BIOS is generally part of the initial encrypted guest image and will be accessed as private guest memory. Add the necessary changes to set up the associated RAM region with a guest_memfd backend to allow for this. Current support centers around using -bios to load the BIOS data. Support for loading the BIOS via pflash requires additional enablement since those interfaces rely on the use of ROM memory regions which make use of the KVM_MEM_READONLY memslot flag, which is not supported for guest_memfd-backed memslots. Signed-off-by: Michael Roth Signed-off-by: Pankaj Gupta Message-ID: <20240530111643.1091816-29-pankaj.gupta@amd.com> Signed-off-by: Paolo Bonzini --- hw/i386/x86-common.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'hw/i386') diff --git a/hw/i386/x86-common.c b/hw/i386/x86-common.c index f41cb0a..c0c66a0 100644 --- a/hw/i386/x86-common.c +++ b/hw/i386/x86-common.c @@ -1001,8 +1001,13 @@ void x86_bios_rom_init(X86MachineState *x86ms, const char *default_firmware, (bios_size % 65536) != 0) { goto bios_error; } - memory_region_init_ram(&x86ms->bios, NULL, "pc.bios", bios_size, - &error_fatal); + if (machine_require_guest_memfd(MACHINE(x86ms))) { + memory_region_init_ram_guest_memfd(&x86ms->bios, NULL, "pc.bios", + bios_size, &error_fatal); + } else { + memory_region_init_ram(&x86ms->bios, NULL, "pc.bios", + bios_size, &error_fatal); + } if (sev_enabled()) { /* * The concept of a "reset" simply doesn't exist for @@ -1023,9 +1028,11 @@ void x86_bios_rom_init(X86MachineState *x86ms, const char *default_firmware, } g_free(filename); - /* map the last 128KB of the BIOS in ISA space */ - x86_isa_bios_init(&x86ms->isa_bios, rom_memory, &x86ms->bios, - !isapc_ram_fw); + if (!machine_require_guest_memfd(MACHINE(x86ms))) { + /* map the last 128KB of the BIOS in ISA space */ + x86_isa_bios_init(&x86ms->isa_bios, rom_memory, &x86ms->bios, + !isapc_ram_fw); + } /* map all the bios at the top of memory */ memory_region_add_subregion(rom_memory, -- cgit v1.1