Re: [RFCv2 20/37] KVM: s390: protvirt: Add new gprs location handling

[Christian Borntraeger <borntraeger@de.ibm.com>]

On 05.02.20 12:18, Thomas Huth wrote:
> On 03/02/2020 14.19, Christian Borntraeger wrote:
>> From: Janosch Frank <frankja@linux.ibm.com>
>>
>> Guest registers for protected guests are stored at offset 0x380.
>>
>> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
>> ---
>>  arch/s390/include/asm/kvm_host.h |  4 +++-
>>  arch/s390/kvm/kvm-s390.c         | 11 +++++++++++
>>  2 files changed, 14 insertions(+), 1 deletion(-)
>>
>> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
>> index f5ca53574406..125511ec6eb0 100644
>> --- a/arch/s390/include/asm/kvm_host.h
>> +++ b/arch/s390/include/asm/kvm_host.h
>> @@ -343,7 +343,9 @@ struct kvm_s390_itdb {
>>  struct sie_page {
>>  	struct kvm_s390_sie_block sie_block;
>>  	struct mcck_volatile_info mcck_info;	/* 0x0200 */
>> -	__u8 reserved218[1000];		/* 0x0218 */
>> +	__u8 reserved218[360];		/* 0x0218 */
>> +	__u64 pv_grregs[16];		/* 0x380 */
> 
> s/0x380/0x0380/ to align with the other comments

Ack. 
> 
>> +	__u8 reserved400[512];
> 
> Maybe add a /* 0x0400 */ comment ... though it's obvious from the name
> already.

ack
> 
>>  	struct kvm_s390_itdb itdb;	/* 0x0600 */
>>  	__u8 reserved700[2304];		/* 0x0700 */
>>  };
>> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
>> index 39bf39a10cf2..1945180b857a 100644
>> --- a/arch/s390/kvm/kvm-s390.c
>> +++ b/arch/s390/kvm/kvm-s390.c
>> @@ -3996,6 +3996,7 @@ static int vcpu_post_run(struct kvm_vcpu *vcpu, int exit_reason)
>>  static int __vcpu_run(struct kvm_vcpu *vcpu)
>>  {
>>  	int rc, exit_reason;
>> +	struct sie_page *sie_page = (struct sie_page *)vcpu->arch.sie_block;
>>  
>>  	/*
>>  	 * We try to hold kvm->srcu during most of vcpu_run (except when run-
>> @@ -4017,8 +4018,18 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
>>  		guest_enter_irqoff();
>>  		__disable_cpu_timer_accounting(vcpu);
>>  		local_irq_enable();
>> +		if (kvm_s390_pv_is_protected(vcpu->kvm)) {
>> +			memcpy(sie_page->pv_grregs,
>> +			       vcpu->run->s.regs.gprs,
>> +			       sizeof(sie_page->pv_grregs));
>> +		}
>>  		exit_reason = sie64a(vcpu->arch.sie_block,
>>  				     vcpu->run->s.regs.gprs);
>> +		if (kvm_s390_pv_is_protected(vcpu->kvm)) {
>> +			memcpy(vcpu->run->s.regs.gprs,
>> +			       sie_page->pv_grregs,
>> +			       sizeof(sie_page->pv_grregs));
>> +		}
>>  		local_irq_disable();
>>  		__enable_cpu_timer_accounting(vcpu);
>>  		guest_exit_irqoff();
>>
> 
> Reviewed-by: Thomas Huth <thuth@redhat.com>
>