Re: [PATCH v7 08/17] KVM: s390: pv: make kvm_s390_cpus_from_pv global

From: Janosch Frank
Date: Mon Feb 07 2022 - 05:26:38 EST


On 2/4/22 16:53, Claudio Imbrenda wrote:
The functions kvm_s390_cpus_from_pv needs to be called from pv.c, so
make it global.


KVM: s390: pv: Add kvm_s390_cpus_from_pv to kvm-s390.h and provide documentation

Future changes make it necessary to call this function from pv.c.

While we're add it let's properly document kvm_s390_cpus_from_pv() and kvm_s390_cpus_to_pv().




Also could you swap patches 8 and 9 so this one is closer to patch #10?

Reviewed-by: Janosch Frank <frankja@xxxxxxxxxxxxx>


Take the opportunity to add documentation.

Signed-off-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx>
---
arch/s390/kvm/kvm-s390.c | 26 +++++++++++++++++++++++++-
arch/s390/kvm/kvm-s390.h | 1 +
2 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 1a788f45d691..0fc8d1aec396 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2175,7 +2175,20 @@ static int kvm_s390_set_cmma_bits(struct kvm *kvm,
return r;
}
-static int kvm_s390_cpus_from_pv(struct kvm *kvm, u16 *rcp, u16 *rrcp)
+/**
+ * kvm_s390_cpus_from_pv - Convert all protected vCPUs in a protected VM to
+ * non protected.
+ * @kvm the VM whose protected vCPUs are to be converted
+ * @rcp return value for the RC field of the UVC (in case of error)
+ * @rrcp return value for the RRC field of the UVC (in case of error)
+ *
+ * Does not stop in case of error, tries to convert as many
+ * CPUs as possible. In case of error, the RC and RRC of the last error are
+ * returned.
+ *
+ * Return: 0 in case of success, otherwise -EIO
+ */
+int kvm_s390_cpus_from_pv(struct kvm *kvm, u16 *rcp, u16 *rrcp)
{
struct kvm_vcpu *vcpu;
u16 rc, rrc;
@@ -2202,6 +2215,17 @@ static int kvm_s390_cpus_from_pv(struct kvm *kvm, u16 *rcp, u16 *rrcp)
return ret;
}
+/**
+ * kvm_s390_cpus_to_pv - Convert all non-protected vCPUs in a protected VM
+ * to protected.
+ * @kvm the VM whose protected vCPUs are to be converted
+ * @rcp return value for the RC field of the UVC (in case of error)
+ * @rrcp return value for the RRC field of the UVC (in case of error)
+ *
+ * Tries to undo the conversion in case of error.
+ *
+ * Return: 0 in case of success, otherwise -EIO
+ */
static int kvm_s390_cpus_to_pv(struct kvm *kvm, u16 *rc, u16 *rrc)
{
unsigned long i;
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 098831e815e6..9276d910631b 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -365,6 +365,7 @@ int kvm_s390_vcpu_setup_cmma(struct kvm_vcpu *vcpu);
void kvm_s390_vcpu_unsetup_cmma(struct kvm_vcpu *vcpu);
void kvm_s390_set_cpu_timer(struct kvm_vcpu *vcpu, __u64 cputm);
__u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu);
+int kvm_s390_cpus_from_pv(struct kvm *kvm, u16 *rcp, u16 *rrcp);
/* implemented in diag.c */
int kvm_s390_handle_diag(struct kvm_vcpu *vcpu);