[RFC,25/37] KVM: s390: protvirt: STSI handling
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Message ID 20191024114059.102802-26-frankja@linux.ibm.com
State New
Headers show
Series
  • KVM: s390: Add support for protected VMs
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Commit Message

Janosch Frank Oct. 24, 2019, 11:40 a.m. UTC
Save response to sidad and disable address checking for protected
guests.

Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
---
 arch/s390/kvm/priv.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

Comments

Thomas Huth Nov. 15, 2019, 8:27 a.m. UTC | #1
On 24/10/2019 13.40, Janosch Frank wrote:
> Save response to sidad and disable address checking for protected
> guests.
> 
> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
> ---
>  arch/s390/kvm/priv.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
> index ed52ffa8d5d4..06c7e7a10825 100644
> --- a/arch/s390/kvm/priv.c
> +++ b/arch/s390/kvm/priv.c
> @@ -872,7 +872,7 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
>  
>  	operand2 = kvm_s390_get_base_disp_s(vcpu, &ar);
>  
> -	if (operand2 & 0xfff)
> +	if (!kvm_s390_pv_is_protected(vcpu->kvm) && (operand2 & 0xfff))
>  		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);

I'd prefer if you could put the calculation of operand2 also under the
!pv if-statement:

	if (!kvm_s390_pv_is_protected(vcpu->kvm)) {
		operand2 = kvm_s390_get_base_disp_s(vcpu, &ar);
		if (operand2 & 0xfff)
			return kvm_s390_inject_program_int(vcpu,
						    PGM_SPECIFICATION);
	}

... that makes it more obvious that operand2 is only valid in the !pv
case and you should get automatic compiler warnings if you use it otherwise.

>  	switch (fc) {
> @@ -893,8 +893,13 @@ static int handle_stsi(struct kvm_vcpu *vcpu)
>  		handle_stsi_3_2_2(vcpu, (void *) mem);
>  		break;
>  	}
> +	if (kvm_s390_pv_is_protected(vcpu->kvm)) {
> +		memcpy((void *)vcpu->arch.sie_block->sidad, (void *)mem,
> +		       PAGE_SIZE);
> +		rc = 0;
> +	} else
> +		rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);

Please also use braces for the else-branch (according to
Documentation/process/coding-style.rst).

 Thomas

Patch
diff mbox series

diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index ed52ffa8d5d4..06c7e7a10825 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -872,7 +872,7 @@  static int handle_stsi(struct kvm_vcpu *vcpu)
 
 	operand2 = kvm_s390_get_base_disp_s(vcpu, &ar);
 
-	if (operand2 & 0xfff)
+	if (!kvm_s390_pv_is_protected(vcpu->kvm) && (operand2 & 0xfff))
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
 	switch (fc) {
@@ -893,8 +893,13 @@  static int handle_stsi(struct kvm_vcpu *vcpu)
 		handle_stsi_3_2_2(vcpu, (void *) mem);
 		break;
 	}
+	if (kvm_s390_pv_is_protected(vcpu->kvm)) {
+		memcpy((void *)vcpu->arch.sie_block->sidad, (void *)mem,
+		       PAGE_SIZE);
+		rc = 0;
+	} else
+		rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
 
-	rc = write_guest(vcpu, operand2, ar, (void *)mem, PAGE_SIZE);
 	if (rc) {
 		rc = kvm_s390_inject_prog_cond(vcpu, rc);
 		goto out;