Mailing List Archive

Add support for FWFT extension in KVM

Signed-off-by: Clément Léger <cleger@rivosinc.com>
---
arch/riscv/include/asm/kvm_host.h | 5 +
arch/riscv/include/asm/kvm_vcpu_sbi.h | 1 +
arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h | 37 ++++++
arch/riscv/include/uapi/asm/kvm.h | 1 +
arch/riscv/kvm/Makefile | 1 +
arch/riscv/kvm/vcpu.c | 5 +
arch/riscv/kvm/vcpu_sbi.c | 4 +
arch/riscv/kvm/vcpu_sbi_fwft.c | 136 +++++++++++++++++++++
8 files changed, 190 insertions(+)
create mode 100644 arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
create mode 100644 arch/riscv/kvm/vcpu_sbi_fwft.c

diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index 484d04a92fa6..be60aaa07f57 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -19,6 +19,7 @@
#include <asm/kvm_vcpu_fp.h>
#include <asm/kvm_vcpu_insn.h>
#include <asm/kvm_vcpu_sbi.h>
+#include <asm/kvm_vcpu_sbi_fwft.h>
#include <asm/kvm_vcpu_timer.h>
#include <asm/kvm_vcpu_pmu.h>

@@ -169,6 +170,7 @@ struct kvm_vcpu_csr {
struct kvm_vcpu_config {
u64 henvcfg;
u64 hstateen0;
+ u64 hedeleg;
};

struct kvm_vcpu_smstateen_csr {
@@ -261,6 +263,9 @@ struct kvm_vcpu_arch {
/* Performance monitoring context */
struct kvm_pmu pmu_context;

+ /* Firmware feature SBI extension context */
+ struct kvm_sbi_fwft fwft_context;
+
/* 'static' configurations which are set only once */
struct kvm_vcpu_config cfg;

diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h
index b96705258cf9..3a33bbacc233 100644
--- a/arch/riscv/include/asm/kvm_vcpu_sbi.h
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h
@@ -86,6 +86,7 @@ extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_dbcn;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_sta;
+extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_fwft;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental;
extern const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor;

diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
new file mode 100644
index 000000000000..7dc1b80c7e6c
--- /dev/null
+++ b/arch/riscv/include/asm/kvm_vcpu_sbi_fwft.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2023 Rivos Inc
+ *
+ * Authors:
+ * Atish Patra <atishp@rivosinc.com>
+ */
+
+#ifndef __KVM_VCPU_RISCV_FWFT_H
+#define __KVM_VCPU_RISCV_FWFT_H
+
+#include <asm/sbi.h>
+
+#define KVM_SBI_FWFT_FEATURE_COUNT 1
+
+struct kvm_sbi_fwft_config;
+struct kvm_vcpu;
+
+struct kvm_sbi_fwft_feature {
+ enum sbi_fwft_feature_t id;
+ int (*set)(struct kvm_vcpu *vcpu, struct kvm_sbi_fwft_config *conf, unsigned long value);
+ int (*get)(struct kvm_vcpu *vcpu, struct kvm_sbi_fwft_config *conf, unsigned long *value);
+};
+
+struct kvm_sbi_fwft_config {
+ const struct kvm_sbi_fwft_feature *feature;
+ unsigned long flags;
+};
+
+/* FWFT data structure per vcpu */
+struct kvm_sbi_fwft {
+ struct kvm_sbi_fwft_config configs[KVM_SBI_FWFT_FEATURE_COUNT];
+};
+
+#define vcpu_to_fwft(vcpu) (&(vcpu)->arch.fwft_context)
+
+#endif /* !__KVM_VCPU_RISCV_FWFT_H */
diff --git a/arch/riscv/include/uapi/asm/kvm.h b/arch/riscv/include/uapi/asm/kvm.h
index 7499e88a947c..fa3097da91c0 100644
--- a/arch/riscv/include/uapi/asm/kvm.h
+++ b/arch/riscv/include/uapi/asm/kvm.h
@@ -185,6 +185,7 @@ enum KVM_RISCV_SBI_EXT_ID {
KVM_RISCV_SBI_EXT_VENDOR,
KVM_RISCV_SBI_EXT_DBCN,
KVM_RISCV_SBI_EXT_STA,
+ KVM_RISCV_SBI_EXT_FWFT,
KVM_RISCV_SBI_EXT_MAX,
};

diff --git a/arch/riscv/kvm/Makefile b/arch/riscv/kvm/Makefile
index c9646521f113..19175bd5b40a 100644
--- a/arch/riscv/kvm/Makefile
+++ b/arch/riscv/kvm/Makefile
@@ -27,6 +27,7 @@ kvm-y += vcpu_sbi_base.o
kvm-y += vcpu_sbi_replace.o
kvm-y += vcpu_sbi_hsm.o
kvm-y += vcpu_sbi_sta.o
+kvm-y += vcpu_sbi_fwft.o
kvm-y += vcpu_timer.o
kvm-$(CONFIG_RISCV_PMU_SBI) += vcpu_pmu.o vcpu_sbi_pmu.o
kvm-y += aia.o
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index b5ca9f2e98ac..461ef60d4eda 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -505,6 +505,8 @@ static void kvm_riscv_vcpu_setup_config(struct kvm_vcpu *vcpu)
if (riscv_isa_extension_available(isa, SMSTATEEN))
cfg->hstateen0 |= SMSTATEEN0_SSTATEEN0;
}
+
+ cfg->hedeleg = csr_read(CSR_HEDELEG);
}

void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
@@ -521,6 +523,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
csr_write(CSR_VSTVAL, csr->vstval);
csr_write(CSR_HVIP, csr->hvip);
csr_write(CSR_VSATP, csr->vsatp);
+ csr_write(CSR_HEDELEG, cfg->hedeleg);
csr_write(CSR_HENVCFG, cfg->henvcfg);
if (IS_ENABLED(CONFIG_32BIT))
csr_write(CSR_HENVCFGH, cfg->henvcfg >> 32);
@@ -551,6 +554,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
struct kvm_vcpu_csr *csr = &vcpu->arch.guest_csr;
+ struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;

vcpu->cpu = -1;

@@ -574,6 +578,7 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
csr->vstval = csr_read(CSR_VSTVAL);
csr->hvip = csr_read(CSR_HVIP);
csr->vsatp = csr_read(CSR_VSATP);
+ cfg->hedeleg = csr_read(CSR_HEDELEG);
}

static void kvm_riscv_check_vcpu_requests(struct kvm_vcpu *vcpu)
diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c
index 72a2ffb8dcd1..76901f0f34b7 100644
--- a/arch/riscv/kvm/vcpu_sbi.c
+++ b/arch/riscv/kvm/vcpu_sbi.c
@@ -74,6 +74,10 @@ static const struct kvm_riscv_sbi_extension_entry sbi_ext[] = {
.ext_idx = KVM_RISCV_SBI_EXT_STA,
.ext_ptr = &vcpu_sbi_ext_sta,
},
+ {
+ .ext_idx = KVM_RISCV_SBI_EXT_FWFT,
+ .ext_ptr = &vcpu_sbi_ext_fwft,
+ },
{
.ext_idx = KVM_RISCV_SBI_EXT_EXPERIMENTAL,
.ext_ptr = &vcpu_sbi_ext_experimental,
diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c
new file mode 100644
index 000000000000..b9b7f8fa6d22
--- /dev/null
+++ b/arch/riscv/kvm/vcpu_sbi_fwft.c
@@ -0,0 +1,136 @@
+// 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/sbi.h>
+#include <asm/kvm_vcpu_sbi.h>
+#include <asm/kvm_vcpu_sbi_fwft.h>
+
+#define MIS_DELEG (1UL << EXC_LOAD_MISALIGNED | 1UL << EXC_STORE_MISALIGNED)
+
+static int kvm_sbi_fwft_set_misaligned_delegation(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ unsigned long value)
+{
+ if (value)
+ csr_set(CSR_HEDELEG, MIS_DELEG);
+ else
+ csr_clear(CSR_HEDELEG, MIS_DELEG);
+
+ return SBI_SUCCESS;
+}
+
+static int kvm_sbi_fwft_get_misaligned_delegation(struct kvm_vcpu *vcpu,
+ struct kvm_sbi_fwft_config *conf,
+ unsigned long *value)
+{
+ *value = (csr_read(CSR_HEDELEG) & MIS_DELEG) != 0;
+
+ return SBI_SUCCESS;
+}
+
+static struct kvm_sbi_fwft_config *
+kvm_sbi_fwft_get_config(struct kvm_vcpu *vcpu, enum sbi_fwft_feature_t feature)
+{
+ int i = 0;
+ struct kvm_sbi_fwft *fwft = vcpu_to_fwft(vcpu);
+
+ for (i = 0; i < KVM_SBI_FWFT_FEATURE_COUNT; i++) {
+ if (fwft->configs[i].feature->id == feature)
+ return &fwft->configs[i];
+ }
+
+ return NULL;
+}
+
+static int kvm_sbi_fwft_set(struct kvm_vcpu *vcpu,
+ enum sbi_fwft_feature_t feature,
+ unsigned long value, unsigned long flags)
+{
+ struct kvm_sbi_fwft_config *conf = kvm_sbi_fwft_get_config(vcpu,
+ feature);
+ if (!conf)
+ return SBI_ERR_DENIED;
+
+ if ((flags & ~SBI_FWFT_SET_FLAG_LOCK) != 0)
+ return SBI_ERR_INVALID_PARAM;
+
+ if (conf->flags & SBI_FWFT_SET_FLAG_LOCK)
+ return SBI_ERR_DENIED;
+
+ conf->flags = flags;
+
+ return conf->feature->set(vcpu, conf, value);
+}
+
+static int kvm_sbi_fwft_get(struct kvm_vcpu *vcpu,
+ enum sbi_fwft_feature_t feature,
+ unsigned long *value)
+{
+ struct kvm_sbi_fwft_config *conf = kvm_sbi_fwft_get_config(vcpu,
+ feature);
+ if (!conf)
+ return SBI_ERR_DENIED;
+
+ return conf->feature->get(vcpu, conf, value);
+}
+
+static int kvm_sbi_ext_fwft_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
+ struct kvm_vcpu_sbi_return *retdata)
+{
+ int ret = 0;
+ struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
+ unsigned long funcid = cp->a6;
+
+ switch (funcid) {
+ case SBI_EXT_FWFT_SET:
+ ret = kvm_sbi_fwft_set(vcpu, cp->a0, cp->a1, cp->a2);
+ break;
+ case SBI_EXT_FWFT_GET:
+ ret = kvm_sbi_fwft_get(vcpu, cp->a0, &retdata->out_val);
+ break;
+ default:
+ ret = SBI_ERR_NOT_SUPPORTED;
+ break;
+ }
+
+ retdata->err_val = ret;
+
+ return 0;
+}
+
+static const struct kvm_sbi_fwft_feature features[] = {
+ {
+ .id = SBI_FWFT_MISALIGNED_DELEG,
+ .set = kvm_sbi_fwft_set_misaligned_delegation,
+ .get = kvm_sbi_fwft_get_misaligned_delegation,
+ }
+};
+
+static_assert(ARRAY_SIZE(features) == KVM_SBI_FWFT_FEATURE_COUNT);
+
+
+static unsigned long kvm_sbi_ext_fwft_probe(struct kvm_vcpu *vcpu)
+{
+ struct kvm_sbi_fwft *fwft = vcpu_to_fwft(vcpu);
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(features); i++)
+ fwft->configs[i].feature = &features[i];
+
+ return 1;
+}
+
+const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_fwft = {
+ .extid_start = SBI_EXT_FWFT,
+ .extid_end = SBI_EXT_FWFT,
+ .handler = kvm_sbi_ext_fwft_handler,
+ .probe = kvm_sbi_ext_fwft_probe,
+};
--
2.43.0