Commit 1945a067 authored by Marc Zyngier's avatar Marc Zyngier Committed by Will Deacon
Browse files

arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0 



Admitedly, passing id_aa64mmfr1.vh=0 on the command-line isn't
that easy to understand, and it is likely that users would much
prefer write "kvm-arm.mode=nvhe", or "...=protected".

So here you go. This has the added advantage that we can now
always honor the "kvm-arm.mode=protected" option, even when
booting on a VHE system.

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Acked-by: default avatarDavid Brazdil <dbrazdil@google.com>
Link: https://lore.kernel.org/r/20210208095732.3267263-18-maz@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 863ace77

Documentation/admin-guide/kernel-parameters.txt

+3 −0
Original line number Diff line number Diff line
@@ -2257,6 +2257,9 @@ 
	kvm-arm.mode=

			[KVM,ARM] Select one of KVM/arm64's modes of operation.



			nvhe: Standard nVHE-based mode, without support for

			      protected guests.



			protected: nVHE-based mode with support for guests whose

				   state is kept private from the host.

				   Not valid if the kernel is running in EL2.

arch/arm64/kernel/idreg-override.c

+2 −0
Original line number Diff line number Diff line
@@ -45,6 +45,8 @@ static const struct { 
	char	alias[FTR_ALIAS_NAME_LEN];

	char	feature[FTR_ALIAS_OPTION_LEN];

} aliases[] __initconst = {

	{ "kvm-arm.mode=nvhe",		"id_aa64mmfr1.vh=0" },

	{ "kvm-arm.mode=protected",	"id_aa64mmfr1.vh=0" },

};



static int __init find_field(const char *cmdline,

arch/arm64/kvm/arm.c

+3 −0
Original line number Diff line number Diff line
@@ -1966,6 +1966,9 @@ static int __init early_kvm_mode_cfg(char *arg) 
		return 0;

	}



	if (strcmp(arg, "nvhe") == 0 && !WARN_ON(is_kernel_in_hyp_mode()))

		return 0;



	return -EINVAL;

}

early_param("kvm-arm.mode", early_kvm_mode_cfg);