Messages in this thread | | | Subject | Re: [PATCH v9 14/22] KVM: s390: interfaces to clear CRYCB masks | From | Tony Krowiak <> | Date | Wed, 15 Aug 2018 13:55:51 -0400 |
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On 08/15/2018 09:10 AM, Cornelia Huck wrote: > On Mon, 13 Aug 2018 17:48:11 -0400 > Tony Krowiak <akrowiak@linux.vnet.ibm.com> wrote: > >> From: Tony Krowiak <akrowiak@linux.ibm.com> >> >> Introduces two new KVM interface to clear the APM, AQM and ADM masks in >> the guest's CRYCB. The VCPUs are taken out of SIE to ensure the VCPUs do >> not get out of sync. >> >> Signed-off-by: Tony Krowiak <akrowiak@linux.ibm.com> >> Acked-by: Halil Pasic <pasic@linux.ibm.com> >> Tested-by: Michael Mueller <mimu@linux.ibm.com> >> Tested-by: Farhan Ali <alifm@linux.ibm.com> >> Tested-by: Pierre Morel <pmorel@linux.ibm.com> >> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> >> --- >> arch/s390/include/asm/kvm_host.h | 3 +++ >> arch/s390/kvm/kvm-s390.c | 15 +++++++++++++++ >> 2 files changed, 18 insertions(+), 0 deletions(-) >> >> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h >> index 4a739d4..07e58d8 100644 >> --- a/arch/s390/include/asm/kvm_host.h >> +++ b/arch/s390/include/asm/kvm_host.h >> @@ -258,6 +258,7 @@ struct kvm_s390_sie_block { >> __u64 tecmc; /* 0x00e8 */ >> __u8 reservedf0[12]; /* 0x00f0 */ >> #define CRYCB_FORMAT_MASK 0x00000003 >> +#define CRYCB_FORMAT0 0x00000000 > This should probably go into a different patch (define is not used > here)?
You are spot on. It needs to go in patch 15 where it is first used.
> >> #define CRYCB_FORMAT1 0x00000001 >> #define CRYCB_FORMAT2 0x00000003 >> __u32 crycbd; /* 0x00fc */ >> @@ -861,6 +862,8 @@ void kvm_arch_async_page_not_present(struct kvm_vcpu *vcpu, >> void kvm_arch_async_page_present(struct kvm_vcpu *vcpu, >> struct kvm_async_pf *work); >> >> +void kvm_arch_crypto_clear_masks(struct kvm *kvm); >> + >> extern int sie64a(struct kvm_s390_sie_block *, u64 *); >> extern char sie_exit; >> >> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c >> index f7de123..8d8a65a 100644 >> --- a/arch/s390/kvm/kvm-s390.c >> +++ b/arch/s390/kvm/kvm-s390.c >> @@ -1919,6 +1919,21 @@ static void kvm_s390_set_crycb_format(struct kvm *kvm) >> kvm->arch.crypto.crycbd |= CRYCB_FORMAT1; >> } >> >> +void kvm_arch_crypto_clear_masks(struct kvm *kvm) >> +{ >> + mutex_lock(&kvm->lock); >> + kvm_s390_vcpu_block_all(kvm); >> + >> + memset(&kvm->arch.crypto.crycb->apcb0, 0, >> + sizeof(kvm->arch.crypto.crycb->apcb0)); >> + memset(&kvm->arch.crypto.crycb->apcb1, 0, >> + sizeof(kvm->arch.crypto.crycb->apcb1)); >> + >> + kvm_s390_vcpu_unblock_all(kvm); >> + mutex_unlock(&kvm->lock); >> +} >> +EXPORT_SYMBOL(kvm_arch_crypto_clear_masks); > A quick grep shows that kvm-related exports tend to be > EXPORT_SYMBOL_GPL. Should that also be done here?
I did some internet searching to find out why the EXPORT_SYMBOL_GPL macro is used rather than EXPORT_SYMBOL. I found the link below which explains why. According to that article, if the EXPORT_SYMBOL_GPL macro is used, modules that do not carry a GPL-compatible license can not use the function. Apparently Linus Trovalds and the lawyers he consulted believe it codifies the intention in code itself makes the code more flexible and a lot less likely to be misunderstood. It is further pointed out that "circumventing the GPL-only export requires an explicit action, making it clear that the copyright infringement was a deliberate act.
Since our modules are GPL-licensed, it would probably behoove us to use the EXPORT_SYMBOL_GPL macro to export this function.
https://lwn.net/Articles/154602/
> >> + >> static u64 kvm_s390_get_initial_cpuid(void) >> { >> struct cpuid cpuid;
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