On 21.02.2018 20:35, Collin L. Walling wrote: > The s390-ccw firmware needs some information in support of the > boot process which is not available on the native machine. > Examples are the netboot firmware load address and now the > boot menu parameters. > > While storing that data in unused fields of the IPL parameter block > works, that approach could create problems if the parameter block > definition should change in the future. Because then a guest could > overwrite these fields using the set IPLB diagnose. > > In fact the data in question is of more global nature and not really > tied to an IPL device, so separating it is rather logical. > > This commit introduces a new structure to hold firmware relevant > IPL parameters set by QEMU. The data is stored at location 204 (dec) > and can contain up to 7 32-bit words. This area is available to > programming in the z/Architecture Principles of Operation and > can thus safely be used by the firmware until the IPL has completed. > > Signed-off-by: Viktor Mihajlovski <mihaj...@linux.vnet.ibm.com> > Signed-off-by: Collin L. Walling <wall...@linux.vnet.ibm.com> > --- > hw/s390x/ipl.c | 18 +++++++++++++++++- > hw/s390x/ipl.h | 25 +++++++++++++++++++++++-- > pc-bios/s390-ccw/iplb.h | 18 ++++++++++++++++-- > pc-bios/s390-ccw/main.c | 6 +++++- > 4 files changed, 61 insertions(+), 6 deletions(-) > > diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c > index 0d06fc1..79f5a58 100644 > --- a/hw/s390x/ipl.c > +++ b/hw/s390x/ipl.c > @@ -399,6 +399,21 @@ void s390_reipl_request(void) > qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET); > } > > +static void s390_ipl_prepare_qipl(S390CPU *cpu) > +{ > + S390IPLState *ipl = get_ipl_device(); > + uint8_t *addr; > + uint64_t len = 4096; > + > + addr = cpu_physical_memory_map(cpu->env.psa, &len, 1); > + if (!addr || len < QIPL_ADDRESS + sizeof(QemuIplParameters)) { > + error_report("Cannot set QEMU IPL parameters"); > + return; > + } > + memcpy(addr + QIPL_ADDRESS, &ipl->qipl, sizeof(QemuIplParameters)); > + cpu_physical_memory_unmap(addr, len, 1, len); > +} > + > void s390_ipl_prepare_cpu(S390CPU *cpu) > { > S390IPLState *ipl = get_ipl_device(); > @@ -418,8 +433,9 @@ void s390_ipl_prepare_cpu(S390CPU *cpu) > error_report_err(err); > vm_stop(RUN_STATE_INTERNAL_ERROR); > } > - ipl->iplb.ccw.netboot_start_addr = cpu_to_be64(ipl->start_addr); > + ipl->qipl.netboot_start_addr = cpu_to_be64(ipl->start_addr); > } > + s390_ipl_prepare_qipl(cpu); > } > > static void s390_ipl_reset(DeviceState *dev) > diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h > index 8a705e0..08926a3 100644 > --- a/hw/s390x/ipl.h > +++ b/hw/s390x/ipl.h > @@ -16,8 +16,7 @@ > #include "cpu.h" > > struct IplBlockCcw { > - uint64_t netboot_start_addr; > - uint8_t reserved0[77]; > + uint8_t reserved0[85]; > uint8_t ssid; > uint16_t devno; > uint8_t vm_flags; > @@ -90,6 +89,27 @@ void s390_ipl_prepare_cpu(S390CPU *cpu); > IplParameterBlock *s390_ipl_get_iplb(void); > void s390_reipl_request(void); > > +#define QIPL_ADDRESS 0xcc > + > +/* > + * The QEMU IPL Parameters will be stored at absolute address > + * 204 (0xcc) which means it is 32-bit word aligned but not > + * double-word aligned. > + * Placement of data fields in this area must account for > + * their alignment needs. E.g., netboot_start_address must > + * have an offset of n * 8 bytes within the struct in order > + * to keep it double-word aligned.
Should that rather be "4 + n * 8" instead of "n * 8" ? Apart from that, patch looks good to me now, so once you've fixed the comment (if necessary): Reviewed-by: Thomas Huth <th...@redhat.com>