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[v4,8/8] RISC-V: KVM: Expose Zicboz to the guest

Message ID 20230209152628.129914-9-ajones@ventanamicro.com (mailing list archive)
State Superseded
Delegated to: Palmer Dabbelt
Headers show
Series RISC-V: Apply Zicboz to clear_page | expand

Checks

Context Check Description
conchuod/tree_selection fail Failed to apply to next/pending-fixes or riscv/for-next

Commit Message

Andrew Jones Feb. 9, 2023, 3:26 p.m. UTC 
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: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
---
 arch/riscv/include/uapi/asm/kvm.h | 1 +
 arch/riscv/kvm/vcpu.c             | 4 ++++
 2 files changed, 5 insertions(+)
diff mbox series

Patch

diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index c1a1bb0fa91c..e44c1e90eaa7 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -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,
 };
 
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index e5126cefbc87..198ee86cad38 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -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)
@@ -865,6 +866,9 @@  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);