Blame SOURCES/kvm-s390-sclp-use-cpu-offset-to-locate-cpu-entries.patch

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From adf66c037e60d66f864960b24c746b767efb10b9 Mon Sep 17 00:00:00 2001
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From: Thomas Huth <thuth@redhat.com>
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Date: Wed, 11 Nov 2020 12:03:10 -0500
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Subject: [PATCH 10/18] s390/sclp: use cpu offset to locate cpu entries
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RH-Author: Thomas Huth <thuth@redhat.com>
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Message-id: <20201111120316.707489-7-thuth@redhat.com>
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Patchwork-id: 99503
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O-Subject: [RHEL-8.4.0 qemu-kvm PATCH v2 06/12] s390/sclp: use cpu offset to locate cpu entries
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Bugzilla: 1798506
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RH-Acked-by: Jens Freimann <jfreimann@redhat.com>
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RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
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RH-Acked-by: David Hildenbrand <david@redhat.com>
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From: Collin Walling <walling@linux.ibm.com>
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The start of the CPU entry region in the Read SCP Info response data is
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denoted by the offset_cpu field. As such, QEMU needs to begin creating
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entries at this address.
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This is in preparation for when Read SCP Info inevitably introduces new
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bytes that push the start of the CPUEntry field further away.
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Read CPU Info is unlikely to ever change, so let's not bother
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accounting for the offset there.
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Signed-off-by: Collin Walling <walling@linux.ibm.com>
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Reviewed-by: Thomas Huth <thuth@redhat.com>
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Reviewed-by: Cornelia Huck <cohuck@redhat.com>
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Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
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Message-Id: <20200915194416.107460-6-walling@linux.ibm.com>
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Signed-off-by: Cornelia Huck <cohuck@redhat.com>
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(cherry picked from commit 1a7a568859473b1cda39a015493c5c82bb200281)
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Signed-off-by: Thomas Huth <thuth@redhat.com>
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Signed-off-by: Danilo C. L. de Paula <ddepaula@redhat.com>
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---
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 hw/s390x/sclp.c | 6 ++++--
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 1 file changed, 4 insertions(+), 2 deletions(-)
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diff --git a/hw/s390x/sclp.c b/hw/s390x/sclp.c
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index 2b4c6c5cfad..017989b3888 100644
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--- a/hw/s390x/sclp.c
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+++ b/hw/s390x/sclp.c
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@@ -89,6 +89,8 @@ static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb)
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     int rnsize, rnmax;
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     IplParameterBlock *ipib = s390_ipl_get_iplb();
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     int required_len = SCCB_REQ_LEN(ReadInfo, machine->possible_cpus->len);
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+    int offset_cpu = offsetof(ReadInfo, entries);
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+    CPUEntry *entries_start = (void *)sccb + offset_cpu;
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     if (be16_to_cpu(sccb->h.length) < required_len) {
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         sccb->h.response_code = cpu_to_be16(SCLP_RC_INSUFFICIENT_SCCB_LENGTH);
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@@ -96,9 +98,9 @@ static void read_SCP_info(SCLPDevice *sclp, SCCB *sccb)
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     }
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     /* CPU information */
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-    prepare_cpu_entries(machine, read_info->entries, &cpu_count);
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+    prepare_cpu_entries(machine, entries_start, &cpu_count);
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     read_info->entries_cpu = cpu_to_be16(cpu_count);
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-    read_info->offset_cpu = cpu_to_be16(offsetof(ReadInfo, entries));
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+    read_info->offset_cpu = cpu_to_be16(offset_cpu);
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     read_info->highest_cpu = cpu_to_be16(machine->smp.max_cpus - 1);
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     read_info->ibc_val = cpu_to_be32(s390_get_ibc_val());
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-- 
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2.27.0
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