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RISC-V: KVM: Reorganize SBI code by moving SBI v0.1 to its own file
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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>
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Atish Patra authored and Anup Patel committed Jan 6, 2022
1 parent cf70be9 commit a046c2d
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Showing 4 changed files with 146 additions and 131 deletions.
2 changes: 2 additions & 0 deletions arch/riscv/include/asm/kvm_vcpu_sbi.h
Original file line number Diff line number Diff line change
Expand Up @@ -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__ */
1 change: 1 addition & 0 deletions arch/riscv/kvm/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -19,4 +19,5 @@ 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
148 changes: 17 additions & 131 deletions arch/riscv/kvm/vcpu_sbi.c
Original file line number Diff line number Diff line change
Expand Up @@ -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)
Expand All @@ -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;

Expand Down Expand Up @@ -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)
{
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,
};

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;
Expand All @@ -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 */
Expand Down Expand Up @@ -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
126 changes: 126 additions & 0 deletions arch/riscv/kvm/vcpu_sbi_v01.c
Original file line number Diff line number Diff line change
@@ -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,
};

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