Messages in this thread | | | Subject | Re: [PATCH v5 10/15] KVM: s390: add functions to (un)register GISC with GISA | From | Michael Mueller <> | Date | Thu, 20 Dec 2018 15:32:00 +0100 |
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On 19.12.18 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 <mimu@linux.ibm.com> > --- > arch/s390/include/asm/kvm_host.h | 9 ++++++ > arch/s390/kvm/interrupt.c | 66 ++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 75 insertions(+) >
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> --- 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)
I will rename this one here as well to gisa_set_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; > + /* > + * Try to set the IAM or loop, if the IPM has changed > + * or the GISA has been inserted into the alert list. > + */ > + _word0 = (word0 & ~0xffUL) | iam; > + } while (cmpxchg(&gisa->u64.word[0], word0, _word0) != _word0); > + > + return 0; > +} > +
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