From: Janosch Frank <frankja@linux.ibm.com>
To: Cornelia Huck <cohuck@redhat.com>
Cc: borntraeger@de.ibm.com, qemu-s390x@nongnu.org,
mihajlov@linux.ibm.com, qemu-devel@nongnu.org
Subject: Re: [PATCH v3 2/4] s390x: Add missing vcpu reset functions
Date: Wed, 4 Dec 2019 10:00:45 +0100 [thread overview]
Message-ID: <a84f5248-8255-0e9d-7253-91d53e4f7765@linux.ibm.com> (raw)
In-Reply-To: <20191203184459.0417a40a.cohuck@redhat.com>
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On 12/3/19 6:44 PM, Cornelia Huck wrote:
> On Tue, 3 Dec 2019 08:28:11 -0500
> Janosch Frank <frankja@linux.ibm.com> wrote:
>
>> Up to now we only had an ioctl to reset vcpu data QEMU couldn't reach
>> for the initial reset, and that was also called for the clear
>> reset. To be architecture compliant, we also need to clear local
>> interrupts on a normal reset.
>>
>> Because of this and the upcoming protvirt support we need to add
>> ioctls for the missing clear and normal resets.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> Reviewed-by: Thomas Huth <thuth@redhat.com>
>> Acked-by: David Hildenbrand <david@redhat.com>
>> ---
>> target/s390x/cpu.c | 16 +++++++++++++--
>> target/s390x/kvm-stub.c | 10 +++++++++-
>> target/s390x/kvm.c | 42 ++++++++++++++++++++++++++++++++--------
>> target/s390x/kvm_s390x.h | 4 +++-
>> 4 files changed, 60 insertions(+), 12 deletions(-)
>>
>> diff --git a/target/s390x/cpu.c b/target/s390x/cpu.c
>> index 829ce6ad54..4973365d6c 100644
>> --- a/target/s390x/cpu.c
>> +++ b/target/s390x/cpu.c
>> @@ -139,8 +139,20 @@ static void s390_cpu_reset(CPUState *s, cpu_reset_type type)
>> }
>>
>> /* Reset state inside the kernel that we cannot access yet from QEMU. */
>
> For the last iteration, I asked about the 'yet' here...
I have not written those comments, I merely refuse to delete them :)
We still reset some state in the kernel, I'm not sure how much of that
is already exposed via ioctls to QEMU, so I won't remove the comment.
>
>> - if (kvm_enabled() && type != S390_CPU_RESET_NORMAL) {
>> - kvm_s390_reset_vcpu(cpu);
>> + if (kvm_enabled()) {
>> + switch (type) {
>> + case S390_CPU_RESET_CLEAR:
>> + kvm_s390_reset_vcpu_clear(cpu);
>> + break;
>> + case S390_CPU_RESET_INITIAL:
>> + kvm_s390_reset_vcpu_initial(cpu);
>> + break;
>> + case S390_CPU_RESET_NORMAL:
>> + kvm_s390_reset_vcpu_normal(cpu);
>> + break;
>> + default:
>> + g_assert_not_reached();
>> + }
>> }
>> }
>>
>
> (...)
>
>> @@ -403,17 +405,41 @@ int kvm_arch_destroy_vcpu(CPUState *cs)
>> return 0;
>> }
>>
>> -void kvm_s390_reset_vcpu(S390CPU *cpu)
>> +static void kvm_s390_reset_vcpu(S390CPU *cpu, unsigned long type)
>> {
>> CPUState *cs = CPU(cpu);
>>
>> - /* The initial reset call is needed here to reset in-kernel
>> - * vcpu data that we can't access directly from QEMU
>> - * (i.e. with older kernels which don't support sync_regs/ONE_REG).
>> - * Before this ioctl cpu_synchronize_state() is called in common kvm
>> - * code (kvm-all) */
>> - if (kvm_vcpu_ioctl(cs, KVM_S390_INITIAL_RESET, NULL)) {
>> - error_report("Initial CPU reset failed on CPU %i", cs->cpu_index);
>> + /*
>> + * The reset call is needed here to reset in-kernel vcpu data that
>> + * we can't access directly from QEMU (i.e. with older kernels
>> + * which don't support sync_regs/ONE_REG). Before this ioctl
>
> ...and this reference to 'older kernels' here.
>
> Are the comments still correct/relevant?
See above
>
>> + * cpu_synchronize_state() is called in common kvm code
>> + * (kvm-all).
>> + */
>> + if (kvm_vcpu_ioctl(cs, type)) {
>> + error_report("CPU reset failed on CPU %i type %lx",
>> + cs->cpu_index, type);
>> + }
>> +}
>
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next prev parent reply other threads:[~2019-12-04 9:12 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-03 13:28 [PATCH v3 0/4] s390x: Increase architectural compliance Janosch Frank
2019-12-03 13:28 ` [PATCH v3 1/4] Header sync Janosch Frank
2019-12-03 13:28 ` [PATCH v3 2/4] s390x: Add missing vcpu reset functions Janosch Frank
2019-12-03 17:44 ` Cornelia Huck
2019-12-04 9:00 ` Janosch Frank [this message]
2019-12-04 9:15 ` Cornelia Huck
2019-12-04 14:59 ` Cornelia Huck
2019-12-04 15:07 ` David Hildenbrand
2019-12-04 15:08 ` David Hildenbrand
2019-12-04 15:33 ` Cornelia Huck
2019-12-04 15:35 ` David Hildenbrand
2019-12-03 13:28 ` [PATCH v3 3/4] s390x: Fix cpu normal reset ri clearing Janosch Frank
2019-12-05 13:32 ` Cornelia Huck
2019-12-03 13:28 ` [PATCH v3 4/4] pc-bios/s390x: Fix reset psw mask Janosch Frank
2019-12-03 13:33 ` Christian Borntraeger
2019-12-03 17:18 ` Cornelia Huck
2019-12-03 17:22 ` Cornelia Huck
2019-12-03 18:32 ` Christian Borntraeger
2019-12-05 10:12 ` Cornelia Huck
2019-12-13 12:06 ` Cornelia Huck
2019-12-13 12:37 ` Janosch Frank
2019-12-17 12:36 ` Thomas Huth
2019-12-17 15:09 ` Thomas Huth
2019-12-18 12:15 ` Janosch Frank
2019-12-18 12:28 ` Cornelia Huck
2019-12-18 16:54 ` Cornelia Huck
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