From 67f7e426e53833a5db75b0d813e8d537b8a75bd2 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Thu, 21 Jul 2022 14:56:36 +0200 Subject: hw/i386: pass RNG seed via setup_data entry MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Tiny machines optimized for fast boot time generally don't use EFI, which means a random seed has to be supplied some other way. For this purpose, Linux (≥5.20) supports passing a seed in the setup_data table with SETUP_RNG_SEED, specially intended for hypervisors, kexec, and specialized bootloaders. The linked commit shows the upstream kernel implementation. At Paolo's request, we don't pass these to versioned machine types ≤7.0. Link: https://git.kernel.org/tip/tip/c/68b8e9713c8 Cc: Marcel Apfelbaum Cc: Paolo Bonzini Cc: Richard Henderson Cc: Eduardo Habkost Cc: Peter Maydell Cc: Philippe Mathieu-Daudé Cc: Laurent Vivier Reviewed-by: Michael S. Tsirkin Signed-off-by: Jason A. Donenfeld Message-Id: <20220721125636.446842-1-Jason@zx2c4.com> Signed-off-by: Paolo Bonzini --- include/hw/i386/pc.h | 3 +++ include/hw/i386/x86.h | 3 ++- include/standard-headers/asm-x86/bootparam.h | 1 + 3 files changed, 6 insertions(+), 1 deletion(-) (limited to 'include') diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h index b7735dc..2a8ffbc 100644 --- a/include/hw/i386/pc.h +++ b/include/hw/i386/pc.h @@ -127,6 +127,9 @@ struct PCMachineClass { /* create kvmclock device even when KVM PV features are not exposed */ bool kvmclock_create_always; + + /* skip passing an rng seed for legacy machines */ + bool legacy_no_rng_seed; }; #define TYPE_PC_MACHINE "generic-pc-machine" diff --git a/include/hw/i386/x86.h b/include/hw/i386/x86.h index 9089bdd..6bdf1f6 100644 --- a/include/hw/i386/x86.h +++ b/include/hw/i386/x86.h @@ -123,7 +123,8 @@ void x86_bios_rom_init(MachineState *ms, const char *default_firmware, void x86_load_linux(X86MachineState *x86ms, FWCfgState *fw_cfg, int acpi_data_size, - bool pvh_enabled); + bool pvh_enabled, + bool legacy_no_rng_seed); bool x86_machine_is_smm_enabled(const X86MachineState *x86ms); bool x86_machine_is_acpi_enabled(const X86MachineState *x86ms); diff --git a/include/standard-headers/asm-x86/bootparam.h b/include/standard-headers/asm-x86/bootparam.h index 072e2ed..b2aaad1 100644 --- a/include/standard-headers/asm-x86/bootparam.h +++ b/include/standard-headers/asm-x86/bootparam.h @@ -10,6 +10,7 @@ #define SETUP_EFI 4 #define SETUP_APPLE_PROPERTIES 5 #define SETUP_JAILHOUSE 6 +#define SETUP_RNG_SEED 9 #define SETUP_INDIRECT (1<<31) -- cgit v1.1