Stop using gmap_enable(), gmap_disable(), gmap_get_enabled().

The correct guest ASCE is passed as a parameter of sie64a(), there is
no need to save the current gmap in lowcore.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Steffen Eiden <seiden@linux.ibm.com>
---
 arch/s390/kvm/kvm-s390.c | 7 +------
 arch/s390/kvm/vsie.c     | 4 +---
 2 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index cfe3f8182aa5..df778a4a011d 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3719,7 +3719,6 @@ __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu)
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 
-	gmap_enable(vcpu->arch.enabled_gmap);
 	kvm_s390_set_cpuflags(vcpu, CPUSTAT_RUNNING);
 	if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
 		__start_cpu_timer_accounting(vcpu);
@@ -3732,8 +3731,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
 	if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
 		__stop_cpu_timer_accounting(vcpu);
 	kvm_s390_clear_cpuflags(vcpu, CPUSTAT_RUNNING);
-	vcpu->arch.enabled_gmap = gmap_get_enabled();
-	gmap_disable(vcpu->arch.enabled_gmap);
 
 }
 
@@ -3751,8 +3748,6 @@ void kvm_arch_vcpu_postcreate(struct kvm_vcpu *vcpu)
 	}
 	if (test_kvm_facility(vcpu->kvm, 74) || vcpu->kvm->arch.user_instr0)
 		vcpu->arch.sie_block->ictl |= ICTL_OPEREXC;
-	/* make vcpu_load load the right gmap on the first trigger */
-	vcpu->arch.enabled_gmap = vcpu->arch.gmap;
 }
 
 static bool kvm_has_pckmo_subfunc(struct kvm *kvm, unsigned long nr)
@@ -4891,7 +4886,7 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
 		}
 		exit_reason = sie64a(vcpu->arch.sie_block,
 				     vcpu->run->s.regs.gprs,
-				     gmap_get_enabled()->asce);
+				     vcpu->arch.gmap->asce);
 		if (kvm_s390_pv_cpu_is_protected(vcpu)) {
 			memcpy(vcpu->run->s.regs.gprs,
 			       sie_page->pv_grregs,
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 35e7dd882148..d03f95e528fe 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -1151,7 +1151,7 @@ static int do_vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	current->thread.gmap_int_code = 0;
 	barrier();
 	if (!kvm_s390_vcpu_sie_inhibited(vcpu))
-		rc = sie64a(scb_s, vcpu->run->s.regs.gprs, gmap_get_enabled()->asce);
+		rc = sie64a(scb_s, vcpu->run->s.regs.gprs, vsie_page->gmap->asce);
 	barrier();
 	vcpu->arch.sie_block->prog0c &= ~PROG_IN_SIE;
 
@@ -1296,10 +1296,8 @@ static int vsie_run(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 		if (!rc)
 			rc = map_prefix(vcpu, vsie_page);
 		if (!rc) {
-			gmap_enable(vsie_page->gmap);
 			update_intervention_requests(vsie_page);
 			rc = do_vsie_run(vcpu, vsie_page);
-			gmap_enable(vcpu->arch.gmap);
 		}
 		atomic_andnot(PROG_BLOCK_SIE, &scb_s->prog20);
 
-- 
2.47.0

On Tue, Oct 15, 2024 at 06:43:21PM +0200, Claudio Imbrenda wrote:
> Stop using gmap_enable(), gmap_disable(), gmap_get_enabled().
> 
> The correct guest ASCE is passed as a parameter of sie64a(), there is
> no need to save the current gmap in lowcore.
> 
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> Acked-by: Steffen Eiden <seiden@linux.ibm.com>
> ---
>  arch/s390/kvm/kvm-s390.c | 7 +------
>  arch/s390/kvm/vsie.c     | 4 +---
>  2 files changed, 2 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index cfe3f8182aa5..df778a4a011d 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -3719,7 +3719,6 @@ __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu)
>  void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
>  {
>  
> -	gmap_enable(vcpu->arch.enabled_gmap);
>  	kvm_s390_set_cpuflags(vcpu, CPUSTAT_RUNNING);
>  	if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
>  		__start_cpu_timer_accounting(vcpu);
> @@ -3732,8 +3731,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
>  	if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
>  		__stop_cpu_timer_accounting(vcpu);
>  	kvm_s390_clear_cpuflags(vcpu, CPUSTAT_RUNNING);
> -	vcpu->arch.enabled_gmap = gmap_get_enabled();
> -	gmap_disable(vcpu->arch.enabled_gmap);

I guess you want to get rid of enabled_gmap as well, since it becomes
unused with this patch:

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 603b56bfccd3..51201b4ac93a 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -750,8 +750,6 @@ struct kvm_vcpu_arch {
 	struct hrtimer    ckc_timer;
 	struct kvm_s390_pgm_info pgm;
 	struct gmap *gmap;
-	/* backup location for the currently enabled gmap when scheduled out */
-	struct gmap *enabled_gmap;
 	struct kvm_guestdbg_info_arch guestdbg;
 	unsigned long pfault_token;
 	unsigned long pfault_select;

Reviewed-by: Heiko Carstens <hca@linux.ibm.com>

On Mon, 21 Oct 2024 11:50:06 +0200
Heiko Carstens <hca@linux.ibm.com> wrote:

> On Tue, Oct 15, 2024 at 06:43:21PM +0200, Claudio Imbrenda wrote:
> > Stop using gmap_enable(), gmap_disable(), gmap_get_enabled().
> > 
> > The correct guest ASCE is passed as a parameter of sie64a(), there is
> > no need to save the current gmap in lowcore.
> > 
> > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
> > Acked-by: Steffen Eiden <seiden@linux.ibm.com>
> > ---
> >  arch/s390/kvm/kvm-s390.c | 7 +------
> >  arch/s390/kvm/vsie.c     | 4 +---
> >  2 files changed, 2 insertions(+), 9 deletions(-)
> > 
> > diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> > index cfe3f8182aa5..df778a4a011d 100644
> > --- a/arch/s390/kvm/kvm-s390.c
> > +++ b/arch/s390/kvm/kvm-s390.c
> > @@ -3719,7 +3719,6 @@ __u64 kvm_s390_get_cpu_timer(struct kvm_vcpu *vcpu)
> >  void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
> >  {
> >  
> > -	gmap_enable(vcpu->arch.enabled_gmap);
> >  	kvm_s390_set_cpuflags(vcpu, CPUSTAT_RUNNING);
> >  	if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
> >  		__start_cpu_timer_accounting(vcpu);
> > @@ -3732,8 +3731,6 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
> >  	if (vcpu->arch.cputm_enabled && !is_vcpu_idle(vcpu))
> >  		__stop_cpu_timer_accounting(vcpu);
> >  	kvm_s390_clear_cpuflags(vcpu, CPUSTAT_RUNNING);
> > -	vcpu->arch.enabled_gmap = gmap_get_enabled();
> > -	gmap_disable(vcpu->arch.enabled_gmap);  
> 
> I guess you want to get rid of enabled_gmap as well, since it becomes
> unused with this patch:

oh yeah, I had missed that.

I guess it can go in the next patch, where things are removed

> 
> diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
> index 603b56bfccd3..51201b4ac93a 100644
> --- a/arch/s390/include/asm/kvm_host.h
> +++ b/arch/s390/include/asm/kvm_host.h
> @@ -750,8 +750,6 @@ struct kvm_vcpu_arch {
>  	struct hrtimer    ckc_timer;
>  	struct kvm_s390_pgm_info pgm;
>  	struct gmap *gmap;
> -	/* backup location for the currently enabled gmap when scheduled out */
> -	struct gmap *enabled_gmap;
>  	struct kvm_guestdbg_info_arch guestdbg;
>  	unsigned long pfault_token;
>  	unsigned long pfault_select;
> 
> Reviewed-by: Heiko Carstens <hca@linux.ibm.com>