Unverified Commit b20f6799 authored by Andrew Jones's avatar Andrew Jones Committed by Palmer Dabbelt
Browse files

RISC-V: KVM: Expose Zicboz to the guest 



Guests may use the cbo.zero instruction when the CPU has the Zicboz
extension and the hypervisor sets henvcfg.CBZE.

Add Zicboz support for KVM guests which may be enabled and
disabled from KVM userspace using the ISA extension ONE_REG API.

Signed-off-by: default avatarAndrew Jones <ajones@ventanamicro.com>
Reviewed-by: default avatarConor Dooley <conor.dooley@microchip.com>
Reviewed-by: default avatarAnup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20230224162631.405473-9-ajones@ventanamicro.com


Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent 665fd886

arch/riscv/include/uapi/asm/kvm.h

+1 −0
Original line number Diff line number Diff line
@@ -106,6 +106,7 @@ enum KVM_RISCV_ISA_EXT_ID { 
	KVM_RISCV_ISA_EXT_SVINVAL,

	KVM_RISCV_ISA_EXT_ZIHINTPAUSE,

	KVM_RISCV_ISA_EXT_ZICBOM,

	KVM_RISCV_ISA_EXT_ZICBOZ,

	KVM_RISCV_ISA_EXT_MAX,

};

arch/riscv/kvm/vcpu.c

+4 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ static const unsigned long kvm_isa_ext_arr[] = { 
	KVM_ISA_EXT_ARR(SVPBMT),

	KVM_ISA_EXT_ARR(ZIHINTPAUSE),

	KVM_ISA_EXT_ARR(ZICBOM),

	KVM_ISA_EXT_ARR(ZICBOZ),

};



static unsigned long kvm_riscv_vcpu_base2isa_ext(unsigned long base_ext)
@@ -872,6 +873,9 @@ static void kvm_riscv_vcpu_update_config(const unsigned long *isa) 
	if (riscv_isa_extension_available(isa, ZICBOM))

		henvcfg |= (ENVCFG_CBIE | ENVCFG_CBCFE);



	if (riscv_isa_extension_available(isa, ZICBOZ))

		henvcfg |= ENVCFG_CBZE;



	csr_write(CSR_HENVCFG, henvcfg);

#ifdef CONFIG_32BIT

	csr_write(CSR_HENVCFGH, henvcfg >> 32);