| Message ID | 20200618222258.23287-6-walling@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | s390: Extended-Length SCCB & DIAGNOSE 0x318 | expand |
On 6/19/20 12:22 AM, Collin Walling wrote: > The start of the CPU entry region in the Read SCP Info response data is > denoted by the offset_cpu field. As such, QEMU needs to begin creating > entries at this address. Note that the length of the Read SCP Info data > (data_len) denotes the same value as the cpu offset. > > This is in preparation of when Read SCP Info inevitably introduces new > bytes that push the start of the CPUEntry field further away. > > Read CPU Info is unlikely to ever change, so let's not bother > accounting for the offset there. > > Signed-off-by: Collin Walling <walling@linux.ibm.com> > Reviewed-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Janosch Frank <frankja@linux.ibm.com> > --- > hw/s390x/sclp.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c > index 772b7b3b01..0dfbe6e5ec 100644 > --- a/hw/s390x/sclp.c > +++ b/hw/s390x/sclp.c > @@ -113,13 +113,14 @@ static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb) > int rnsize, rnmax; > IplParameterBlock *ipib = s390_ipl_get_iplb(); > int data_len = get_read_scp_info_data_len(); > + CPUEntry *entries_start = (void *)sccb + data_len; > > if (!sccb_sufficient_len(sccb, machine->possible_cpus->len, data_len)) { > return; > } > > /* CPU information */ > - prepare_cpu_entries(machine, read_info->entries, &cpu_count); > + prepare_cpu_entries(machine, entries_start, &cpu_count); > read_info->entries_cpu = cpu_to_be16(cpu_count); > read_info->offset_cpu = cpu_to_be16(data_len); > read_info->highest_cpu = cpu_to_be16(machine->smp.max_cpus - 1); >
On Thu, 18 Jun 2020 18:22:55 -0400 Collin Walling <walling@linux.ibm.com> wrote: > The start of the CPU entry region in the Read SCP Info response data is > denoted by the offset_cpu field. As such, QEMU needs to begin creating > entries at this address. Note that the length of the Read SCP Info data > (data_len) denotes the same value as the cpu offset. > > This is in preparation of when Read SCP Info inevitably introduces new > bytes that push the start of the CPUEntry field further away. > > Read CPU Info is unlikely to ever change, so let's not bother > accounting for the offset there. > > Signed-off-by: Collin Walling <walling@linux.ibm.com> > Reviewed-by: Thomas Huth <thuth@redhat.com> > --- > hw/s390x/sclp.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Reviewed-by: Cornelia Huck <cohuck@redhat.com>
diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c index 772b7b3b01..0dfbe6e5ec 100644 --- a/hw/s390x/sclp.c +++ b/hw/s390x/sclp.c @@ -113,13 +113,14 @@ static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb) int rnsize, rnmax; IplParameterBlock *ipib = s390_ipl_get_iplb(); int data_len = get_read_scp_info_data_len(); + CPUEntry *entries_start = (void *)sccb + data_len; if (!sccb_sufficient_len(sccb, machine->possible_cpus->len, data_len)) { return; } /* CPU information */ - prepare_cpu_entries(machine, read_info->entries, &cpu_count); + prepare_cpu_entries(machine, entries_start, &cpu_count); read_info->entries_cpu = cpu_to_be16(cpu_count); read_info->offset_cpu = cpu_to_be16(data_len); read_info->highest_cpu = cpu_to_be16(machine->smp.max_cpus - 1);