RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own file

With SBI v0.2, there may be more SBI extensions in future. It makes more
sense to group related extensions in separate files. Guest kernel will
choose appropriate SBI version dynamically.

Move the existing implementation to a separate file so that it can be
removed in future without much conflict.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>

1 files changed, 126 insertions, 0 deletions

diff --git a/arch/riscv/kvm/vcpu_sbi_v01.c b/arch/riscv/kvm/vcpu_sbi_v01.c
new file mode 100644
index 000000000000..4c7e13ec9ccc
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_sbi_v01.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2021 Western Digital Corporation or its affiliates.
+ *
+ * Authors:
+ *     Atish Patra <atish.patra@wdc.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <asm/csr.h>
+#include <asm/sbi.h>
+#include <asm/kvm_vcpu_timer.h>
+#include <asm/kvm_vcpu_sbi.h>
+
+static void kvm_sbi_system_shutdown(struct kvm_vcpu *vcpu,
+				    struct kvm_run *run, u32 type)
+{
+	unsigned long i;
+	struct kvm_vcpu *tmp;
+
+	kvm_for_each_vcpu(i, tmp, vcpu->kvm)
+		tmp->arch.power_off = true;
+	kvm_make_all_cpus_request(vcpu->kvm, KVM_REQ_SLEEP);
+
+	memset(&run->system_event, 0, sizeof(run->system_event));
+	run->system_event.type = type;
+	run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
+}
+
+static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
+				      unsigned long *out_val,
+				      struct kvm_cpu_trap *utrap,
+				      bool *exit)
+{
+	ulong hmask;
+	int i, ret = 0;
+	u64 next_cycle;
+	struct kvm_vcpu *rvcpu;
+	struct cpumask cm, hm;
+	struct kvm *kvm = vcpu->kvm;
+	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+
+	switch (cp->a7) {
+	case SBI_EXT_0_1_CONSOLE_GETCHAR:
+	case SBI_EXT_0_1_CONSOLE_PUTCHAR:
+		/*
+		 * The CONSOLE_GETCHAR/CONSOLE_PUTCHAR SBI calls cannot be
+		 * handled in kernel so we forward these to user-space
+		 */
+		kvm_riscv_vcpu_sbi_forward(vcpu, run);
+		*exit = true;
+		break;
+	case SBI_EXT_0_1_SET_TIMER:
+#if __riscv_xlen == 32
+		next_cycle = ((u64)cp->a1 << 32) | (u64)cp->a0;
+#else
+		next_cycle = (u64)cp->a0;
+#endif
+		ret = kvm_riscv_vcpu_timer_next_event(vcpu, next_cycle);
+		break;
+	case SBI_EXT_0_1_CLEAR_IPI:
+		ret = kvm_riscv_vcpu_unset_interrupt(vcpu, IRQ_VS_SOFT);
+		break;
+	case SBI_EXT_0_1_SEND_IPI:
+		if (cp->a0)
+			hmask = kvm_riscv_vcpu_unpriv_read(vcpu, false, cp->a0,
+							   utrap);
+		else
+			hmask = (1UL << atomic_read(&kvm->online_vcpus)) - 1;
+		if (utrap->scause)
+			break;
+
+		for_each_set_bit(i, &hmask, BITS_PER_LONG) {
+			rvcpu = kvm_get_vcpu_by_id(vcpu->kvm, i);
+			ret = kvm_riscv_vcpu_set_interrupt(rvcpu, IRQ_VS_SOFT);
+			if (ret < 0)
+				break;
+		}
+		break;
+	case SBI_EXT_0_1_SHUTDOWN:
+		kvm_sbi_system_shutdown(vcpu, run, KVM_SYSTEM_EVENT_SHUTDOWN);
+		*exit = true;
+		break;
+	case SBI_EXT_0_1_REMOTE_FENCE_I:
+	case SBI_EXT_0_1_REMOTE_SFENCE_VMA:
+	case SBI_EXT_0_1_REMOTE_SFENCE_VMA_ASID:
+		if (cp->a0)
+			hmask = kvm_riscv_vcpu_unpriv_read(vcpu, false, cp->a0,
+							   utrap);
+		else
+			hmask = (1UL << atomic_read(&kvm->online_vcpus)) - 1;
+		if (utrap->scause)
+			break;
+
+		cpumask_clear(&cm);
+		for_each_set_bit(i, &hmask, BITS_PER_LONG) {
+			rvcpu = kvm_get_vcpu_by_id(vcpu->kvm, i);
+			if (rvcpu->cpu < 0)
+				continue;
+			cpumask_set_cpu(rvcpu->cpu, &cm);
+		}
+		riscv_cpuid_to_hartid_mask(&cm, &hm);
+		if (cp->a7 == SBI_EXT_0_1_REMOTE_FENCE_I)
+			ret = sbi_remote_fence_i(cpumask_bits(&hm));
+		else if (cp->a7 == SBI_EXT_0_1_REMOTE_SFENCE_VMA)
+			ret = sbi_remote_hfence_vvma(cpumask_bits(&hm),
+						cp->a1, cp->a2);
+		else
+			ret = sbi_remote_hfence_vvma_asid(cpumask_bits(&hm),
+						cp->a1, cp->a2, cp->a3);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	};
+
+	return ret;
+}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01 = {
+	.extid_start = SBI_EXT_0_1_SET_TIMER,
+	.extid_end = SBI_EXT_0_1_SHUTDOWN,
+	.handler = kvm_sbi_ext_v01_handler,
+};