On Thu, Feb 2, 2023 at 9:31 AM Anup Patel <anup@xxxxxxxxxxxxxx> wrote: > > On Thu, Feb 2, 2023 at 4:42 AM Atish Patra <atishp@xxxxxxxxxxxx> wrote: > > > > Currently, the SBI extension handle is expected to return Linux error code. > > The top SBI layer converts the Linux error code to SBI specific error code > > that can be returned to guest invoking the SBI calls. This model works > > as long as SBI error codes have 1-to-1 mappings between them. > > However, that may not be true always. This patch attempts to disassociate > > both these error codes by allowing the SBI extension implementation to > > return SBI specific error codes as well. > > > > The extension will continue to return the Linux error specific code which > > will indicate any problem *with* the extension emulation while the > > SBI specific error will indicate the problem *of* the emulation. > > > > Suggested-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx> > > Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx> > > --- > > arch/riscv/include/asm/kvm_vcpu_sbi.h | 10 ++++- > > arch/riscv/kvm/vcpu_sbi.c | 61 +++++++++++---------------- > > arch/riscv/kvm/vcpu_sbi_base.c | 36 +++++++--------- > > arch/riscv/kvm/vcpu_sbi_hsm.c | 28 ++++++------ > > arch/riscv/kvm/vcpu_sbi_replace.c | 43 +++++++++---------- > > arch/riscv/kvm/vcpu_sbi_v01.c | 18 ++++---- > > 6 files changed, 90 insertions(+), 106 deletions(-) > > > > diff --git a/arch/riscv/include/asm/kvm_vcpu_sbi.h b/arch/riscv/include/asm/kvm_vcpu_sbi.h > > index 45ba341..8425556 100644 > > --- a/arch/riscv/include/asm/kvm_vcpu_sbi.h > > +++ b/arch/riscv/include/asm/kvm_vcpu_sbi.h > > @@ -18,6 +18,13 @@ struct kvm_vcpu_sbi_context { > > int return_handled; > > }; > > > > +struct kvm_vcpu_sbi_return { > > + unsigned long out_val; > > + unsigned long err_val; > > + struct kvm_cpu_trap *utrap; > > This should not be a pointer. Ignore this comment. This is better otherwise we will have circular header dependency. Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx> Thanks, Anup > > > + bool uexit; > > +}; > > + > > struct kvm_vcpu_sbi_extension { > > unsigned long extid_start; > > unsigned long extid_end; > > @@ -27,8 +34,7 @@ struct kvm_vcpu_sbi_extension { > > * specific error codes. > > */ > > int (*handler)(struct kvm_vcpu *vcpu, struct kvm_run *run, > > - unsigned long *out_val, struct kvm_cpu_trap *utrap, > > - bool *exit); > > + struct kvm_vcpu_sbi_return *retdata); > > > > /* Extension specific probe function */ > > unsigned long (*probe)(struct kvm_vcpu *vcpu); > > diff --git a/arch/riscv/kvm/vcpu_sbi.c b/arch/riscv/kvm/vcpu_sbi.c > > index f96991d..fe2897e 100644 > > --- a/arch/riscv/kvm/vcpu_sbi.c > > +++ b/arch/riscv/kvm/vcpu_sbi.c > > @@ -12,26 +12,6 @@ > > #include <asm/sbi.h> > > #include <asm/kvm_vcpu_sbi.h> > > > > -static int kvm_linux_err_map_sbi(int err) > > -{ > > - switch (err) { > > - case 0: > > - return SBI_SUCCESS; > > - case -EPERM: > > - return SBI_ERR_DENIED; > > - case -EINVAL: > > - return SBI_ERR_INVALID_PARAM; > > - case -EFAULT: > > - return SBI_ERR_INVALID_ADDRESS; > > - case -EOPNOTSUPP: > > - return SBI_ERR_NOT_SUPPORTED; > > - case -EALREADY: > > - return SBI_ERR_ALREADY_AVAILABLE; > > - default: > > - return SBI_ERR_FAILURE; > > - }; > > -} > > - > > #ifndef CONFIG_RISCV_SBI_V01 > > static const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_v01 = { > > .extid_start = -1UL, > > @@ -125,11 +105,14 @@ int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) > > { > > int ret = 1; > > bool next_sepc = true; > > - bool userspace_exit = false; > > struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > > const struct kvm_vcpu_sbi_extension *sbi_ext; > > - struct kvm_cpu_trap utrap = { 0 }; > > - unsigned long out_val = 0; > > + struct kvm_cpu_trap utrap = {0}; > > + struct kvm_vcpu_sbi_return sbi_ret = { > > + .out_val = 0, > > + .err_val = 0, > > + .utrap = &utrap, > > + }; > > bool ext_is_v01 = false; > > > > sbi_ext = kvm_vcpu_sbi_find_ext(cp->a7); > > @@ -139,42 +122,46 @@ int kvm_riscv_vcpu_sbi_ecall(struct kvm_vcpu *vcpu, struct kvm_run *run) > > cp->a7 <= SBI_EXT_0_1_SHUTDOWN) > > ext_is_v01 = true; > > #endif > > - ret = sbi_ext->handler(vcpu, run, &out_val, &utrap, &userspace_exit); > > + ret = sbi_ext->handler(vcpu, run, &sbi_ret); > > } else { > > /* Return error for unsupported SBI calls */ > > cp->a0 = SBI_ERR_NOT_SUPPORTED; > > goto ecall_done; > > } > > > > + /* > > + * When the SBI extension returns a Linux error code, it exits the ioctl > > + * loop and forwards the error to userspace. > > + */ > > + if (ret < 0) { > > + next_sepc = false; > > + goto ecall_done; > > + } > > + > > /* Handle special error cases i.e trap, exit or userspace forward */ > > - if (utrap.scause) { > > + if (sbi_ret.utrap->scause) { > > /* No need to increment sepc or exit ioctl loop */ > > ret = 1; > > - utrap.sepc = cp->sepc; > > - kvm_riscv_vcpu_trap_redirect(vcpu, &utrap); > > + sbi_ret.utrap->sepc = cp->sepc; > > + kvm_riscv_vcpu_trap_redirect(vcpu, sbi_ret.utrap); > > next_sepc = false; > > goto ecall_done; > > } > > > > /* Exit ioctl loop or Propagate the error code the guest */ > > - if (userspace_exit) { > > + if (sbi_ret.uexit) { > > next_sepc = false; > > ret = 0; > > } else { > > - /** > > - * SBI extension handler always returns an Linux error code. Convert > > - * it to the SBI specific error code that can be propagated the SBI > > - * caller. > > - */ > > - ret = kvm_linux_err_map_sbi(ret); > > - cp->a0 = ret; > > + cp->a0 = sbi_ret.err_val; > > ret = 1; > > } > > ecall_done: > > if (next_sepc) > > cp->sepc += 4; > > - if (!ext_is_v01) > > - cp->a1 = out_val; > > + /* a1 should only be updated when we continue the ioctl loop */ > > + if (!ext_is_v01 && ret == 1) > > + cp->a1 = sbi_ret.out_val; > > > > return ret; > > } > > diff --git a/arch/riscv/kvm/vcpu_sbi_base.c b/arch/riscv/kvm/vcpu_sbi_base.c > > index 846d518..69f4202 100644 > > --- a/arch/riscv/kvm/vcpu_sbi_base.c > > +++ b/arch/riscv/kvm/vcpu_sbi_base.c > > @@ -14,24 +14,22 @@ > > #include <asm/kvm_vcpu_sbi.h> > > > > static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > - unsigned long *out_val, > > - struct kvm_cpu_trap *trap, bool *exit) > > + struct kvm_vcpu_sbi_return *retdata) > > { > > - int ret = 0; > > struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > > const struct kvm_vcpu_sbi_extension *sbi_ext; > > > > switch (cp->a6) { > > case SBI_EXT_BASE_GET_SPEC_VERSION: > > - *out_val = (KVM_SBI_VERSION_MAJOR << > > + retdata->out_val = (KVM_SBI_VERSION_MAJOR << > > SBI_SPEC_VERSION_MAJOR_SHIFT) | > > KVM_SBI_VERSION_MINOR; > > break; > > case SBI_EXT_BASE_GET_IMP_ID: > > - *out_val = KVM_SBI_IMPID; > > + retdata->out_val = KVM_SBI_IMPID; > > break; > > case SBI_EXT_BASE_GET_IMP_VERSION: > > - *out_val = LINUX_VERSION_CODE; > > + retdata->out_val = LINUX_VERSION_CODE; > > break; > > case SBI_EXT_BASE_PROBE_EXT: > > if ((cp->a0 >= SBI_EXT_EXPERIMENTAL_START && > > @@ -43,33 +41,33 @@ static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > * forward it to the userspace > > */ > > kvm_riscv_vcpu_sbi_forward(vcpu, run); > > - *exit = true; > > + retdata->uexit = true; > > } else { > > sbi_ext = kvm_vcpu_sbi_find_ext(cp->a0); > > if (sbi_ext) { > > if (sbi_ext->probe) > > - *out_val = sbi_ext->probe(vcpu); > > + retdata->out_val = sbi_ext->probe(vcpu); > > else > > - *out_val = 1; > > + retdata->out_val = 1; > > } else > > - *out_val = 0; > > + retdata->out_val = 0; > > } > > break; > > case SBI_EXT_BASE_GET_MVENDORID: > > - *out_val = vcpu->arch.mvendorid; > > + retdata->out_val = vcpu->arch.mvendorid; > > break; > > case SBI_EXT_BASE_GET_MARCHID: > > - *out_val = vcpu->arch.marchid; > > + retdata->out_val = vcpu->arch.marchid; > > break; > > case SBI_EXT_BASE_GET_MIMPID: > > - *out_val = vcpu->arch.mimpid; > > + retdata->out_val = vcpu->arch.mimpid; > > break; > > default: > > - ret = -EOPNOTSUPP; > > + retdata->err_val = SBI_ERR_NOT_SUPPORTED; > > break; > > } > > > > - return ret; > > + return 0; > > } > > > > const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base = { > > @@ -79,17 +77,15 @@ const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base = { > > }; > > > > static int kvm_sbi_ext_forward_handler(struct kvm_vcpu *vcpu, > > - struct kvm_run *run, > > - unsigned long *out_val, > > - struct kvm_cpu_trap *utrap, > > - bool *exit) > > + struct kvm_run *run, > > + struct kvm_vcpu_sbi_return *retdata) > > { > > /* > > * Both SBI experimental and vendor extensions are > > * unconditionally forwarded to userspace. > > */ > > kvm_riscv_vcpu_sbi_forward(vcpu, run); > > - *exit = true; > > + retdata->uexit = true; > > return 0; > > } > > > > diff --git a/arch/riscv/kvm/vcpu_sbi_hsm.c b/arch/riscv/kvm/vcpu_sbi_hsm.c > > index 619ac0f..7dca0e9 100644 > > --- a/arch/riscv/kvm/vcpu_sbi_hsm.c > > +++ b/arch/riscv/kvm/vcpu_sbi_hsm.c > > @@ -21,9 +21,9 @@ static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu) > > > > target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); > > if (!target_vcpu) > > - return -EINVAL; > > + return SBI_ERR_INVALID_PARAM; > > if (!target_vcpu->arch.power_off) > > - return -EALREADY; > > + return SBI_ERR_ALREADY_AVAILABLE; > > > > reset_cntx = &target_vcpu->arch.guest_reset_context; > > /* start address */ > > @@ -42,7 +42,7 @@ static int kvm_sbi_hsm_vcpu_start(struct kvm_vcpu *vcpu) > > static int kvm_sbi_hsm_vcpu_stop(struct kvm_vcpu *vcpu) > > { > > if (vcpu->arch.power_off) > > - return -EACCES; > > + return SBI_ERR_FAILURE; > > > > kvm_riscv_vcpu_power_off(vcpu); > > > > @@ -57,7 +57,7 @@ static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu) > > > > target_vcpu = kvm_get_vcpu_by_id(vcpu->kvm, target_vcpuid); > > if (!target_vcpu) > > - return -EINVAL; > > + return SBI_ERR_INVALID_PARAM; > > if (!target_vcpu->arch.power_off) > > return SBI_HSM_STATE_STARTED; > > else if (vcpu->stat.generic.blocking) > > @@ -67,9 +67,7 @@ static int kvm_sbi_hsm_vcpu_get_status(struct kvm_vcpu *vcpu) > > } > > > > static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > - unsigned long *out_val, > > - struct kvm_cpu_trap *utrap, > > - bool *exit) > > + struct kvm_vcpu_sbi_return *retdata) > > { > > int ret = 0; > > struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > > @@ -88,27 +86,29 @@ static int kvm_sbi_ext_hsm_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > case SBI_EXT_HSM_HART_STATUS: > > ret = kvm_sbi_hsm_vcpu_get_status(vcpu); > > if (ret >= 0) { > > - *out_val = ret; > > - ret = 0; > > + retdata->out_val = ret; > > + retdata->err_val = 0; > > } > > - break; > > + return 0; > > case SBI_EXT_HSM_HART_SUSPEND: > > switch (cp->a0) { > > case SBI_HSM_SUSPEND_RET_DEFAULT: > > kvm_riscv_vcpu_wfi(vcpu); > > break; > > case SBI_HSM_SUSPEND_NON_RET_DEFAULT: > > - ret = -EOPNOTSUPP; > > + ret = SBI_ERR_NOT_SUPPORTED; > > break; > > default: > > - ret = -EINVAL; > > + ret = SBI_ERR_INVALID_PARAM; > > } > > break; > > default: > > - ret = -EOPNOTSUPP; > > + ret = SBI_ERR_NOT_SUPPORTED; > > } > > > > - return ret; > > + retdata->err_val = ret; > > + > > + return 0; > > } > > > > const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_hsm = { > > diff --git a/arch/riscv/kvm/vcpu_sbi_replace.c b/arch/riscv/kvm/vcpu_sbi_replace.c > > index 03a0198..38fa4c0 100644 > > --- a/arch/riscv/kvm/vcpu_sbi_replace.c > > +++ b/arch/riscv/kvm/vcpu_sbi_replace.c > > @@ -14,15 +14,15 @@ > > #include <asm/kvm_vcpu_sbi.h> > > > > static int kvm_sbi_ext_time_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > - unsigned long *out_val, > > - struct kvm_cpu_trap *utrap, bool *exit) > > + struct kvm_vcpu_sbi_return *retdata) > > { > > - int ret = 0; > > struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > > u64 next_cycle; > > > > - if (cp->a6 != SBI_EXT_TIME_SET_TIMER) > > - return -EINVAL; > > + if (cp->a6 != SBI_EXT_TIME_SET_TIMER) { > > + retdata->err_val = SBI_ERR_INVALID_PARAM; > > + return 0; > > + } > > > > #if __riscv_xlen == 32 > > next_cycle = ((u64)cp->a1 << 32) | (u64)cp->a0; > > @@ -31,7 +31,7 @@ static int kvm_sbi_ext_time_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > #endif > > kvm_riscv_vcpu_timer_next_event(vcpu, next_cycle); > > > > - return ret; > > + return 0; > > } > > > > const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_time = { > > @@ -41,8 +41,7 @@ const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_time = { > > }; > > > > static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > - unsigned long *out_val, > > - struct kvm_cpu_trap *utrap, bool *exit) > > + struct kvm_vcpu_sbi_return *retdata) > > { > > int ret = 0; > > unsigned long i; > > @@ -51,8 +50,10 @@ static int kvm_sbi_ext_ipi_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > unsigned long hmask = cp->a0; > > unsigned long hbase = cp->a1; > > > > - if (cp->a6 != SBI_EXT_IPI_SEND_IPI) > > - return -EINVAL; > > + if (cp->a6 != SBI_EXT_IPI_SEND_IPI) { > > + retdata->err_val = SBI_ERR_INVALID_PARAM; > > + return 0; > > + } > > > > kvm_for_each_vcpu(i, tmp, vcpu->kvm) { > > if (hbase != -1UL) { > > @@ -76,10 +77,8 @@ const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_ipi = { > > }; > > > > static int kvm_sbi_ext_rfence_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > - unsigned long *out_val, > > - struct kvm_cpu_trap *utrap, bool *exit) > > + struct kvm_vcpu_sbi_return *retdata) > > { > > - int ret = 0; > > struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > > unsigned long hmask = cp->a0; > > unsigned long hbase = cp->a1; > > @@ -116,10 +115,10 @@ static int kvm_sbi_ext_rfence_handler(struct kvm_vcpu *vcpu, struct kvm_run *run > > */ > > break; > > default: > > - ret = -EOPNOTSUPP; > > + retdata->err_val = SBI_ERR_NOT_SUPPORTED; > > } > > > > - return ret; > > + return 0; > > } > > > > const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence = { > > @@ -130,14 +129,12 @@ const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_rfence = { > > > > static int kvm_sbi_ext_srst_handler(struct kvm_vcpu *vcpu, > > struct kvm_run *run, > > - unsigned long *out_val, > > - struct kvm_cpu_trap *utrap, bool *exit) > > + struct kvm_vcpu_sbi_return *retdata) > > { > > struct kvm_cpu_context *cp = &vcpu->arch.guest_context; > > unsigned long funcid = cp->a6; > > u32 reason = cp->a1; > > u32 type = cp->a0; > > - int ret = 0; > > > > switch (funcid) { > > case SBI_EXT_SRST_RESET: > > @@ -146,24 +143,24 @@ static int kvm_sbi_ext_srst_handler(struct kvm_vcpu *vcpu, > > kvm_riscv_vcpu_sbi_system_reset(vcpu, run, > > KVM_SYSTEM_EVENT_SHUTDOWN, > > reason); > > - *exit = true; > > + retdata->uexit = true; > > break; > > case SBI_SRST_RESET_TYPE_COLD_REBOOT: > > case SBI_SRST_RESET_TYPE_WARM_REBOOT: > > kvm_riscv_vcpu_sbi_system_reset(vcpu, run, > > KVM_SYSTEM_EVENT_RESET, > > reason); > > - *exit = true; > > + retdata->uexit = true; > > break; > > default: > > - ret = -EOPNOTSUPP; > > + retdata->err_val = SBI_ERR_NOT_SUPPORTED; > > } > > break; > > default: > > - ret = -EOPNOTSUPP; > > + retdata->err_val = SBI_ERR_NOT_SUPPORTED; > > } > > > > - return ret; > > + return 0; > > } > > > > const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_srst = { > > diff --git a/arch/riscv/kvm/vcpu_sbi_v01.c b/arch/riscv/kvm/vcpu_sbi_v01.c > > index 489f225..0269e08 100644 > > --- a/arch/riscv/kvm/vcpu_sbi_v01.c > > +++ b/arch/riscv/kvm/vcpu_sbi_v01.c > > @@ -14,9 +14,7 @@ > > #include <asm/kvm_vcpu_sbi.h> > > > > 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) > > + struct kvm_vcpu_sbi_return *retdata) > > { > > ulong hmask; > > int i, ret = 0; > > @@ -33,7 +31,7 @@ static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > * handled in kernel so we forward these to user-space > > */ > > kvm_riscv_vcpu_sbi_forward(vcpu, run); > > - *exit = true; > > + retdata->uexit = true; > > break; > > case SBI_EXT_0_1_SET_TIMER: > > #if __riscv_xlen == 32 > > @@ -49,10 +47,10 @@ static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > case SBI_EXT_0_1_SEND_IPI: > > if (cp->a0) > > hmask = kvm_riscv_vcpu_unpriv_read(vcpu, false, cp->a0, > > - utrap); > > + retdata->utrap); > > else > > hmask = (1UL << atomic_read(&kvm->online_vcpus)) - 1; > > - if (utrap->scause) > > + if (retdata->utrap->scause) > > break; > > > > for_each_set_bit(i, &hmask, BITS_PER_LONG) { > > @@ -65,17 +63,17 @@ static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > case SBI_EXT_0_1_SHUTDOWN: > > kvm_riscv_vcpu_sbi_system_reset(vcpu, run, > > KVM_SYSTEM_EVENT_SHUTDOWN, 0); > > - *exit = true; > > + retdata->uexit = 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); > > + retdata->utrap); > > else > > hmask = (1UL << atomic_read(&kvm->online_vcpus)) - 1; > > - if (utrap->scause) > > + if (retdata->utrap->scause) > > break; > > > > if (cp->a7 == SBI_EXT_0_1_REMOTE_FENCE_I) > > @@ -103,7 +101,7 @@ static int kvm_sbi_ext_v01_handler(struct kvm_vcpu *vcpu, struct kvm_run *run, > > } > > break; > > default: > > - ret = -EINVAL; > > + retdata->err_val = SBI_ERR_NOT_SUPPORTED; > > break; > > } > > > > -- > > 2.25.1 > > > > Regards, > Anup