RISC-V: KVM: Expose Zicbom to the guest

Guests may use the cbo.inval,clean,flush instructions when the
CPU has the Zicbom extension and the hypervisor sets henvcfg.CBIE
(for cbo.inval) and henvcfg.CBCFE (for cbo.clean,flush).

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

Also opportunistically switch the other isa extension checks in
kvm_riscv_vcpu_update_config() to riscv_isa_extension_available().

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index 3d77713005672c239eb5ca59d6990d937f2e2e1d..8985ff234c01cd03ce660dfaad7cf5abedfd2a78 100644 (file)
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -101,6 +101,7 @@ enum KVM_RISCV_ISA_EXT_ID {
        KVM_RISCV_ISA_EXT_SSTC,
        KVM_RISCV_ISA_EXT_SVINVAL,
        KVM_RISCV_ISA_EXT_ZIHINTPAUSE,
+       KVM_RISCV_ISA_EXT_ZICBOM,
        KVM_RISCV_ISA_EXT_MAX,
 };
 

diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index b0a0ce6d16ef56833e527af916a7c00e9e138e52..f55d15a8a410fc7908ccb5a5c6e5715cdde149c0 100644 (file)
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -59,6 +59,7 @@ static const unsigned long kvm_isa_ext_arr[] = {
        KVM_ISA_EXT_ARR(SVINVAL),
        KVM_ISA_EXT_ARR(SVPBMT),
        KVM_ISA_EXT_ARR(ZIHINTPAUSE),
+       KVM_ISA_EXT_ARR(ZICBOM),
 };
 
 static unsigned long kvm_riscv_vcpu_base2isa_ext(unsigned long base_ext)
@@ -799,11 +800,15 @@ static void kvm_riscv_vcpu_update_config(const unsigned long *isa)
 {
        u64 henvcfg = 0;
 
-       if (__riscv_isa_extension_available(isa, RISCV_ISA_EXT_SVPBMT))
+       if (riscv_isa_extension_available(isa, SVPBMT))
                henvcfg |= ENVCFG_PBMTE;
 
-       if (__riscv_isa_extension_available(isa, RISCV_ISA_EXT_SSTC))
+       if (riscv_isa_extension_available(isa, SSTC))
                henvcfg |= ENVCFG_STCE;
+
+       if (riscv_isa_extension_available(isa, ZICBOM))
+               henvcfg |= (ENVCFG_CBIE | ENVCFG_CBCFE);
+
        csr_write(CSR_HENVCFG, henvcfg);
 #ifdef CONFIG_32BIT
        csr_write(CSR_HENVCFGH, henvcfg >> 32);