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Date:   Thu, 14 Apr 2022 09:20:34 +0200
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Subject: Re: [PATCH v5 11/21] KVM: s390: pci: do initial setup for AEN
 interpretation
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To:     Matthew Rosato <mjrosato@linux.ibm.com>, linux-s390@vger.kernel.org
Cc:     alex.williamson@redhat.com, cohuck@redhat.com,
        schnelle@linux.ibm.com, farman@linux.ibm.com, pmorel@linux.ibm.com,
        hca@linux.ibm.com, gor@linux.ibm.com,
        gerald.schaefer@linux.ibm.com, agordeev@linux.ibm.com,
        svens@linux.ibm.com, frankja@linux.ibm.com, david@redhat.com,
        imbrenda@linux.ibm.com, vneethv@linux.ibm.com,
        oberpar@linux.ibm.com, freude@linux.ibm.com, thuth@redhat.com,
        pasic@linux.ibm.com, pbonzini@redhat.com, corbet@lwn.net,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-doc@vger.kernel.org
References: <20220404174349.58530-1-mjrosato@linux.ibm.com>
 <20220404174349.58530-12-mjrosato@linux.ibm.com>
From:   Christian Borntraeger <borntraeger@linux.ibm.com>
In-Reply-To: <20220404174349.58530-12-mjrosato@linux.ibm.com>
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Precedence: bulk


Am 04.04.22 um 19:43 schrieb Matthew Rosato:
> Initial setup for Adapter Event Notification Interpretation for zPCI
> passthrough devices.  Specifically, allocate a structure for forwarding of
> adapter events and pass the address of this structure to firmware.
> 
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
[...]
>   
> diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
> index 156d1c25a3c1..9db6f8080f71 100644
> --- a/arch/s390/kvm/kvm-s390.c
> +++ b/arch/s390/kvm/kvm-s390.c
> @@ -47,6 +47,7 @@
>   #include <asm/fpu/api.h>
>   #include "kvm-s390.h"
>   #include "gaccess.h"
> +#include "pci.h"
>   
>   #define CREATE_TRACE_POINTS
>   #include "trace.h"
> @@ -502,6 +503,14 @@ int kvm_arch_init(void *opaque)
>   		goto out;
>   	}
>   
> +	if (kvm_s390_pci_interp_allowed()) {
> +		rc = kvm_s390_pci_init();
> +		if (rc) {
> +			pr_err("Unable to allocate AIFT for PCI\n");
> +			goto out;
> +		}
> +	}
> +
>   	rc = kvm_s390_gib_init(GAL_ISC);
>   	if (rc)
>   		goto out;

We would not free the aift that was allocated by kvm_s390_pci_init
in kvm_arch_exit.
Wouldnt we re-allocate a new aift when we unload/reload kvm forgetting about the old one?


> diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c
[...]
> +static int zpci_setup_aipb(u8 nisc)
[...]
> +	size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
> +						sizeof(struct zpci_gaite)));
[...]
> +	if (zpci_set_irq_ctrl(SIC_SET_AENI_CONTROLS, 0, zpci_aipb)) {
> +		rc = -EIO;
> +		goto free_gait;
> +	}
> +
> +	return 0;
> +
> +free_gait:
> +	size = get_order(PAGE_ALIGN(ZPCI_NR_DEVICES *
> +				    sizeof(struct zpci_gaite)));

size should still be valid here?

> +	free_pages((unsigned long)aift->gait, size);
> +free_sbv:
> +	airq_iv_release(aift->sbv);
> +	zpci_aif_sbv = 0;
> +free_aipb:
> +	kfree(zpci_aipb);
> +	zpci_aipb = 0;
> +
> +	return rc;
> +}
> +

The remaining parts look sane.