From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pierre Morel Subject: Re: [PATCH v5 10/15] KVM: s390: add functions to (un)register GISC with GISA Date: Wed, 2 Jan 2019 19:26:18 +0100 Message-ID: <78ce8dfa-1346-f133-de90-7ac5ed7fe008@linux.ibm.com> References: <20181219191756.57973-1-mimu@linux.ibm.com> <20181219191756.57973-11-mimu@linux.ibm.com> Reply-To: pmorel@linux.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format="flowed" Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Michael Mueller , KVM Mailing List Cc: Linux-S390 Mailing List , linux-kernel@vger.kernel.org, kvm390-list@tuxmaker.boeblingen.de.ibm.com, Martin Schwidefsky , Heiko Carstens , Christian Borntraeger , Janosch Frank , David Hildenbrand , Cornelia Huck , Halil Pasic List-ID: On 02/01/2019 18:29, Pierre Morel wrote: > On 19/12/2018 20:17, Michael Mueller wrote: >> Add the IAM (Interruption Alert Mask) to the architecture specific >> kvm struct. This mask in the GISA is used to define for which ISC >> a GIB alert can be issued. >> >> The functions kvm_s390_gisc_register() and kvm_s390_gisc_unregister() >> are used to (un)register a GISC (guest ISC) with a virtual machine and >> its GISA. >> >> Upon successful completion, kvm_s390_gisc_register() returns the >> ISC to be used for GIB alert interruptions. A negative return code >> indicates an error during registration. >> >> Theses functions will be used by other adapter types like AP and PCI to >> request pass-through interruption support. >> >> Signed-off-by: Michael Mueller >> --- >>   arch/s390/include/asm/kvm_host.h |  9 ++++++ >>   arch/s390/kvm/interrupt.c        | 66 >> ++++++++++++++++++++++++++++++++++++++++ >>   2 files changed, 75 insertions(+) >> >> diff --git a/arch/s390/include/asm/kvm_host.h >> b/arch/s390/include/asm/kvm_host.h >> index 0deba3ae8bc7..2c1259da3636 100644 >> --- a/arch/s390/include/asm/kvm_host.h >> +++ b/arch/s390/include/asm/kvm_host.h >> @@ -782,6 +782,9 @@ struct kvm_s390_gisa { >>               u8  reserved03[11]; >>               u32 airq_count; >>           } g1; >> +        struct { >> +            u64 word[4]; >> +        } u64; >>       }; >>   }; >> @@ -849,6 +852,9 @@ struct kvm_arch{ >>       DECLARE_BITMAP(cpu_feat, KVM_S390_VM_CPU_FEAT_NR_BITS); >>       struct kvm_s390_gisa *gisa; >>       int gib_in_use; >> +    u8 iam; >> +    u32 iam_ref_count[MAX_ISC + 1]; >> +    spinlock_t iam_ref_lock; >>   }; >>   #define KVM_HVA_ERR_BAD        (-1UL) >> @@ -882,6 +888,9 @@ void kvm_arch_crypto_set_masks(struct kvm *kvm, >> unsigned long *apm, >>   extern int sie64a(struct kvm_s390_sie_block *, u64 *); >>   extern char sie_exit; >> +extern int kvm_s390_gisc_register(struct kvm *kvm, u32 gisc); >> +extern int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc); >> + >>   static inline void kvm_arch_hardware_disable(void) {} >>   static inline void kvm_arch_check_processor_compat(void *rtn) {} >>   static inline void kvm_arch_sync_events(struct kvm *kvm) {} >> diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c >> index 5a54360cecfe..1cc3ad2e6c7e 100644 >> --- a/arch/s390/kvm/interrupt.c >> +++ b/arch/s390/kvm/interrupt.c >> @@ -229,6 +229,25 @@ static inline u8 int_word_to_isc(u32 int_word) >>    */ >>   #define IPM_BIT_OFFSET (offsetof(struct kvm_s390_gisa, ipm) * >> BITS_PER_BYTE) >> +static inline int set_iam(struct kvm_s390_gisa *gisa, u8 iam) >> +{ >> +    u64 word0, _word0; >> + >> +    do { >> +        word0 = READ_ONCE(gisa->u64.word[0]); >> +        /* If the GISA is in the alert list, do nothing. */ >> +        if ((u64)gisa != word0 >> 32) >> +            return -EBUSY; > > In kvm_s390_gisa_clear() you do: > > +        nullify_gisa(kvm->arch.gisa); > +        set_iam(kvm->arch.gisa, kvm->arch.iam); > > IIUC this call to set_iam() will always fail. Hum, sorry, I oversaw a patch which corrected this problem. Sorry for the noise. (I should have seen it since I copied the right lines!) Regards, Pierre -- Pierre Morel Linux/KVM/QEMU in Böblingen - Germany