From: Anup Patel apatel@ventanamicro.com
[ Upstream commit d808f0b1be4888a87524164bc7dad2242734de38 ]
The SEED CSR access from VS/VU mode (guest) will always trap to HS-mode (KVM) when Zkr extension is available to the Guest/VM.
Forward this CSR access to KVM user space so that it can be emulated based on the method chosen by VMM.
Fixes: f370b4e668f0 ("RISC-V: KVM: Allow scalar crypto extensions for Guest/VM") Signed-off-by: Anup Patel apatel@ventanamicro.com Reviewed-by: Andrew Jones ajones@ventanamicro.com Signed-off-by: Anup Patel anup@brainfault.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/riscv/kvm/vcpu_insn.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
diff --git a/arch/riscv/kvm/vcpu_insn.c b/arch/riscv/kvm/vcpu_insn.c index 7a6abed41bc17..ee7215f4071f5 100644 --- a/arch/riscv/kvm/vcpu_insn.c +++ b/arch/riscv/kvm/vcpu_insn.c @@ -7,6 +7,8 @@ #include <linux/bitops.h> #include <linux/kvm_host.h>
+#include <asm/cpufeature.h> + #define INSN_OPCODE_MASK 0x007c #define INSN_OPCODE_SHIFT 2 #define INSN_OPCODE_SYSTEM 28 @@ -213,9 +215,20 @@ struct csr_func { unsigned long wr_mask); };
+static int seed_csr_rmw(struct kvm_vcpu *vcpu, unsigned int csr_num, + unsigned long *val, unsigned long new_val, + unsigned long wr_mask) +{ + if (!riscv_isa_extension_available(vcpu->arch.isa, ZKR)) + return KVM_INSN_ILLEGAL_TRAP; + + return KVM_INSN_EXIT_TO_USER_SPACE; +} + static const struct csr_func csr_funcs[] = { KVM_RISCV_VCPU_AIA_CSR_FUNCS KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS + { .base = CSR_SEED, .count = 1, .func = seed_csr_rmw }, };
/**