| Message ID | 20240527134811.342027-1-alexei.filippov@syntacore.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v7] target/riscv/kvm/kvm-cpu.c: kvm_riscv_handle_sbi() fail with vendor-specific SBI | expand |
On Mon, May 27, 2024 at 04:48:11PM GMT, Alexei Filippov wrote: > kvm_riscv_handle_sbi() may return not supported return code to not > trigger qemu abort with vendor-specific sbi. > > Add new error path to provide proper error in case of > qemu_chr_fe_read_all() may not return sizeof(ch), because exactly zero > just means we failed to read input, which can happen, so > telling the SBI caller we failed to read, but telling the caller of this > function that we successfully emulated the SBI call, is correct. However, > anything else, other than sizeof(ch), means something unexpected happened, > so we should return an error. > > Added SBI related return code's defines. > > Signed-off-by: Alexei Filippov <alexei.filippov@syntacore.com> > Fixes: 4eb47125 ("target/riscv: Handle KVM_EXIT_RISCV_SBI exit") > --- > Changes since v6: > - Add appropriate commit message. > - Fix error handling according to Andrew Jones suggestion. > target/riscv/kvm/kvm-cpu.c | 11 +++++++---- > target/riscv/sbi_ecall_interface.h | 12 ++++++++++++ > 2 files changed, 19 insertions(+), 4 deletions(-) > > diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c > index f9dbc18a76..a84bcda9d9 100644 > --- a/target/riscv/kvm/kvm-cpu.c > +++ b/target/riscv/kvm/kvm-cpu.c > @@ -1173,16 +1173,19 @@ static int kvm_riscv_handle_sbi(CPUState *cs, struct kvm_run *run) > ret = qemu_chr_fe_read_all(serial_hd(0)->be, &ch, sizeof(ch)); > if (ret == sizeof(ch)) { > run->riscv_sbi.ret[0] = ch; > + ret = 0; ret is already zero here, so this assignment isn't necessary. > } else { > - run->riscv_sbi.ret[0] = -1; > + if (ret == 0) { > + run->riscv_sbi.ret[0] = SBI_ERR_FAILURE; > + } > + ret = -1; > } > - ret = 0; > break; v6 was closer to being correct than this. It should be @@ -1515,21 +1516,24 @@ static int kvm_riscv_handle_sbi(CPUState *cs, struct kvm_run *run) ret = qemu_chr_fe_read_all(serial_hd(0)->be, &ch, sizeof(ch)); if (ret == sizeof(ch)) { run->riscv_sbi.ret[0] = ch; - } else { + } else if (ret == 0) { run->riscv_sbi.ret[0] = -1; + } else { + ret = -1; } - ret = 0; break; > default: > qemu_log_mask(LOG_UNIMP, > - "%s: un-handled SBI EXIT, specific reasons is %lu\n", > + "%s: Unhandled SBI exit with extension-id %lu\n", > __func__, run->riscv_sbi.extension_id); > - ret = -1; > + run->riscv_sbi.ret[0] = SBI_ERR_NOT_SUPPORTED; > break; > } > return ret; > diff --git a/target/riscv/sbi_ecall_interface.h b/target/riscv/sbi_ecall_interface.h > index 43899d08f6..a2e21d9b8c 100644 > --- a/target/riscv/sbi_ecall_interface.h > +++ b/target/riscv/sbi_ecall_interface.h > @@ -69,4 +69,16 @@ > #define SBI_EXT_VENDOR_END 0x09FFFFFF > /* clang-format on */ > > +/* SBI return error codes */ > +#define SBI_SUCCESS 0 > +#define SBI_ERR_FAILURE -1 > +#define SBI_ERR_NOT_SUPPORTED -2 > +#define SBI_ERR_INVALID_PARAM -3 > +#define SBI_ERR_DENIED -4 > +#define SBI_ERR_INVALID_ADDRESS -5 > +#define SBI_ERR_ALREADY_AVAILABLE -6 > +#define SBI_ERR_ALREADY_STARTED -7 > +#define SBI_ERR_ALREADY_STOPPED -8 > +#define SBI_ERR_NO_SHMEM -9 > + > #endif > -- > 2.34.1 > Thanks, drew
diff --git a/target/riscv/kvm/kvm-cpu.c b/target/riscv/kvm/kvm-cpu.c index f9dbc18a76..a84bcda9d9 100644 --- a/target/riscv/kvm/kvm-cpu.c +++ b/target/riscv/kvm/kvm-cpu.c @@ -1173,16 +1173,19 @@ static int kvm_riscv_handle_sbi(CPUState *cs, struct kvm_run *run) ret = qemu_chr_fe_read_all(serial_hd(0)->be, &ch, sizeof(ch)); if (ret == sizeof(ch)) { run->riscv_sbi.ret[0] = ch; + ret = 0; } else { - run->riscv_sbi.ret[0] = -1; + if (ret == 0) { + run->riscv_sbi.ret[0] = SBI_ERR_FAILURE; + } + ret = -1; } - ret = 0; break; default: qemu_log_mask(LOG_UNIMP, - "%s: un-handled SBI EXIT, specific reasons is %lu\n", + "%s: Unhandled SBI exit with extension-id %lu\n", __func__, run->riscv_sbi.extension_id); - ret = -1; + run->riscv_sbi.ret[0] = SBI_ERR_NOT_SUPPORTED; break; } return ret; diff --git a/target/riscv/sbi_ecall_interface.h b/target/riscv/sbi_ecall_interface.h index 43899d08f6..a2e21d9b8c 100644 --- a/target/riscv/sbi_ecall_interface.h +++ b/target/riscv/sbi_ecall_interface.h @@ -69,4 +69,16 @@ #define SBI_EXT_VENDOR_END 0x09FFFFFF /* clang-format on */ +/* SBI return error codes */ +#define SBI_SUCCESS 0 +#define SBI_ERR_FAILURE -1 +#define SBI_ERR_NOT_SUPPORTED -2 +#define SBI_ERR_INVALID_PARAM -3 +#define SBI_ERR_DENIED -4 +#define SBI_ERR_INVALID_ADDRESS -5 +#define SBI_ERR_ALREADY_AVAILABLE -6 +#define SBI_ERR_ALREADY_STARTED -7 +#define SBI_ERR_ALREADY_STOPPED -8 +#define SBI_ERR_NO_SHMEM -9 + #endif
kvm_riscv_handle_sbi() may return not supported return code to not trigger qemu abort with vendor-specific sbi. Add new error path to provide proper error in case of qemu_chr_fe_read_all() may not return sizeof(ch), because exactly zero just means we failed to read input, which can happen, so telling the SBI caller we failed to read, but telling the caller of this function that we successfully emulated the SBI call, is correct. However, anything else, other than sizeof(ch), means something unexpected happened, so we should return an error. Added SBI related return code's defines. Signed-off-by: Alexei Filippov <alexei.filippov@syntacore.com> Fixes: 4eb47125 ("target/riscv: Handle KVM_EXIT_RISCV_SBI exit") --- Changes since v6: - Add appropriate commit message. - Fix error handling according to Andrew Jones suggestion. target/riscv/kvm/kvm-cpu.c | 11 +++++++---- target/riscv/sbi_ecall_interface.h | 12 ++++++++++++ 2 files changed, 19 insertions(+), 4 deletions(-)