On 05.03.19 08:14, Thomas Huth wrote:
> There are some fields in our struct LowCore which apparently have
> been copied from a very old version of the Linux kernel. These
> fields are not architected in the "Principles of Operation", and
> only used on these memory locations in Linux kernels older than
> 2.6.29. Newer Linux kernels moved the entries to different locations
> or are not using them at all anymore. Thus we should never access
> these fields from the QEMU side, so they should be removed.
>
> While we're at it, also add a QEMU_BUILD_BUG_MSG() statement to
> assert that struct LowCore has the right size.
>
> Signed-off-by: Thomas Huth <th...@redhat.com>
> ---
> v2: Now really added the QEMU_BUILD_BUG_MSG()
>
> target/s390x/internal.h | 41 ++---------------------------------------
> 1 file changed, 2 insertions(+), 39 deletions(-)
>
> diff --git a/target/s390x/internal.h b/target/s390x/internal.h
> index 7baf0e2..84ce090 100644
> --- a/target/s390x/internal.h
> +++ b/target/s390x/internal.h
> @@ -63,45 +63,7 @@ typedef struct LowCore {
> PSW program_new_psw; /* 0x1d0 */
> PSW mcck_new_psw; /* 0x1e0 */
> PSW io_new_psw; /* 0x1f0 */
> - PSW return_psw; /* 0x200 */
> - uint8_t irb[64]; /* 0x210 */
> - uint64_t sync_enter_timer; /* 0x250 */
> - uint64_t async_enter_timer; /* 0x258 */
> - uint64_t exit_timer; /* 0x260 */
> - uint64_t last_update_timer; /* 0x268 */
> - uint64_t user_timer; /* 0x270 */
> - uint64_t system_timer; /* 0x278 */
> - uint64_t last_update_clock; /* 0x280 */
> - uint64_t steal_clock; /* 0x288 */
> - PSW return_mcck_psw; /* 0x290 */
> - uint8_t pad9[0xc00 - 0x2a0]; /* 0x2a0 */
> - /* System info area */
> - uint64_t save_area[16]; /* 0xc00 */
> - uint8_t pad10[0xd40 - 0xc80]; /* 0xc80 */
> - uint64_t kernel_stack; /* 0xd40 */
> - uint64_t thread_info; /* 0xd48 */
> - uint64_t async_stack; /* 0xd50 */
> - uint64_t kernel_asce; /* 0xd58 */
> - uint64_t user_asce; /* 0xd60 */
> - uint64_t panic_stack; /* 0xd68 */
> - uint64_t user_exec_asce; /* 0xd70 */
> - uint8_t pad11[0xdc0 - 0xd78]; /* 0xd78 */
> -
> - /* SMP info area: defined by DJB */
> - uint64_t clock_comparator; /* 0xdc0 */
> - uint64_t ext_call_fast; /* 0xdc8 */
> - uint64_t percpu_offset; /* 0xdd0 */
> - uint64_t current_task; /* 0xdd8 */
> - uint32_t softirq_pending; /* 0xde0 */
> - uint32_t pad_0x0de4; /* 0xde4 */
> - uint64_t int_clock; /* 0xde8 */
> - uint8_t pad12[0xe00 - 0xdf0]; /* 0xdf0 */
> -
> - /* 0xe00 is used as indicator for dump tools */
> - /* whether the kernel died with panic() or not */
> - uint32_t panic_magic; /* 0xe00 */
> -
> - uint8_t pad13[0x11b0 - 0xe04]; /* 0xe04 */
> + uint8_t pad13[0x11b0 - 0x200]; /* 0x200 */
>
> uint64_t mcesad; /* 0x11B0 */
>
> @@ -130,6 +92,7 @@ typedef struct LowCore {
>
> uint8_t pad18[0x2000 - 0x1400]; /* 0x1400 */
> } QEMU_PACKED LowCore;
> +QEMU_BUILD_BUG_MSG(sizeof(LowCore) != 8192, "size of LowCore");
I don't consider this message any useful. It is literally self
documenting code what we have here.
Anyhow,
Reviewed-by: David Hildenbrand <da...@redhat.com>
--
Thanks,
David / dhildenb
