From:   Atish Patra <atishp@rivosinc.com>
To:     linux-kernel@vger.kernel.org
Cc:     Atish Patra <atish.patra@wdc.com>, Anup Patel <anup.patel@wdc.com>,
        Atish Patra <atishp@rivosinc.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Heinrich Schuchardt <xypron.glpk@gmx.de>,
        Kefeng Wang <wangkefeng.wang@huawei.com>,
        kvm-riscv@lists.infradead.org, kvm@vger.kernel.org,
        linux-riscv@lists.infradead.org,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Paul Walmsley <paul.walmsley@sifive.com>
Subject: [PATCH v5 2/5] RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own file
Date:   Thu, 18 Nov 2021 00:39:09 -0800
Message-Id: <20211118083912.981995-3-atishp@rivosinc.com>
In-Reply-To: <20211118083912.981995-1-atishp@rivosinc.com>
References: <20211118083912.981995-1-atishp@rivosinc.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
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From: Atish Patra <atish.patra@wdc.com>

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.

Reviewed-by: Anup Patel <anup.patel@wdc.com>
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/include/asm/kvm_vcpu_sbi.h |   2 +
 arch/riscv/kvm/Makefile               |   1 +
 arch/riscv/kvm/vcpu_sbi.c             | 148 +++-----------------------
 arch/riscv/kvm/vcpu_sbi_v01.c         | 126 ++++++++++++++++++++++
 4 files changed, 146 insertions(+), 131 deletions(-)
 create mode 100644 arch/riscv/kvm/vcpu_sbi_v01.c

diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
index 1a4cb0db2d0b..704151969ceb 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
@@ -25,5 +25,7 @@ struct kvm_vcpu_sbi_extension {
 		       bool *exit);
 };
 
+void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run);
 const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(unsigned long extid);
+
 #endif /* __RISCV_KVM_VCPU_SBI_H__ */
diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
index 30cdd1df0098..d3d5ff3a6019 100644
--- a/arch/riscv/kvm/Makefile
+++ b/arch/riscv/kvm/Makefile
@@ -23,4 +23,5 @@ kvm-y += vcpu_exit.o
 kvm-y += vcpu_fp.o
 kvm-y += vcpu_switch.o
 kvm-y += vcpu_sbi.o
+kvm-$(CONFIG_RISCV_SBI_V01) += vcpu_sbi_v01.o
 kvm-y += vcpu_timer.o
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index 32376906ff20..a8e0191cd9fc 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -9,9 +9,7 @@
 #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 int kvm_linux_err_map_sbi(int err)
@@ -32,8 +30,21 @@ static int kvm_linux_err_map_sbi(int err)
 	};
 }
 
-static void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu,
-				       struct kvm_run *run)
+#ifdef CONFIG_RISCV_SBI_V01
+extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01;
+#else
+static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01 = {
+	.extid_start = -1UL,
+	.extid_end = -1UL,
+	.handler = NULL,
+};
+#endif
+
+static const struct kvm_vcpu_sbi_extension *sbi_ext[] = {
+	&vcpu_sbi_ext_v01,
+};
+
+void kvm_riscv_vcpu_sbi_forward(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
 	struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
 
@@ -71,123 +82,6 @@ int kvm_riscv_vcpu_sbi_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	return 0;
 }
 
-#ifdef CONFIG_RISCV_SBI_V01
-
-static void kvm_sbi_system_shutdown(struct kvm_vcpu *vcpu,
-				    struct kvm_run *run, u32 type)
-{
-	int 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,
-};
-
-static const struct kvm_vcpu_sbi_extension *sbi_ext[] = {
-	&vcpu_sbi_ext_v01,
-};
-
 const struct kvm_vcpu_sbi_extension *kvm_vcpu_sbi_find_ext(unsigned long extid)
 {
 	int i = 0;
@@ -214,9 +108,11 @@ int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 	sbi_ext = kvm_vcpu_sbi_find_ext(cp->a7);
 	if (sbi_ext && sbi_ext->handler) {
+#ifdef CONFIG_RISCV_SBI_V01
 		if (cp->a7 >= SBI_EXT_0_1_SET_TIMER &&
 		    cp->a7 <= SBI_EXT_0_1_SHUTDOWN)
 			ext_is_v01 = true;
+#endif
 		ret = sbi_ext->handler(vcpu, run, &out_val, &utrap, &userspace_exit);
 	} else {
 		/* Return error for unsupported SBI calls */
@@ -256,13 +152,3 @@ int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run)
 
 	return ret;
 }
-
-#else
-
-int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run)
-{
-	kvm_riscv_vcpu_sbi_forward(vcpu, run);
-	return 0;
-}
-
-#endif
diff --git a/arch/riscv/kvm/vcpu_sbi_v01.c b/arch/riscv/kvm/vcpu_sbi_v01.c
new file mode 100644
index 000000000000..08097d1c13c1
--- /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)
+{
+	int 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,
+};
-- 
2.33.1