Message-ID: <2a5ec1f1-a0f4-9c55-38df-c48dfe9234f7@linux.ibm.com>
Date:   Wed, 8 Dec 2021 13:59:17 +0100
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Subject: Re: [PATCH 06/32] s390/airq: allow for airq structure that uses an
 input vector
Content-Language: en-US
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,
        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, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20211207205743.150299-1-mjrosato@linux.ibm.com>
 <20211207205743.150299-7-mjrosato@linux.ibm.com>
From:   Christian Borntraeger <borntraeger@linux.ibm.com>
In-Reply-To: <20211207205743.150299-7-mjrosato@linux.ibm.com>
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Precedence: bulk


Am 07.12.21 um 21:57 schrieb Matthew Rosato:
> When doing device passthrough where interrupts are being forwarded
> from host to guest, we wish to use a pinned section of guest memory
> as the vector (the same memory used by the guest as the vector).
> 
> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
> ---
>   arch/s390/include/asm/airq.h     |  4 +++-
>   arch/s390/pci/pci_irq.c          |  8 ++++----
>   drivers/s390/cio/airq.c          | 10 +++++++---
>   drivers/s390/virtio/virtio_ccw.c |  2 +-
>   4 files changed, 15 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/s390/include/asm/airq.h b/arch/s390/include/asm/airq.h
> index 7918a7d09028..e82e5626e139 100644
> --- a/arch/s390/include/asm/airq.h
> +++ b/arch/s390/include/asm/airq.h
> @@ -47,8 +47,10 @@ struct airq_iv {
>   #define AIRQ_IV_PTR		4	/* Allocate the ptr array */
>   #define AIRQ_IV_DATA		8	/* Allocate the data array */
>   #define AIRQ_IV_CACHELINE	16	/* Cacheline alignment for the vector */
> +#define AIRQ_IV_GUESTVEC	32	/* Vector is a pinned guest page */
>   
> -struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags);
> +struct airq_iv *airq_iv_create(unsigned long bits, unsigned long flags,
> +			       unsigned long *vec);
>   void airq_iv_release(struct airq_iv *iv);
>   unsigned long airq_iv_alloc(struct airq_iv *iv, unsigned long num);
>   void airq_iv_free(struct airq_iv *iv, unsigned long bit, unsigned long num);
> diff --git a/arch/s390/pci/pci_irq.c b/arch/s390/pci/pci_irq.c
> index 880bcd73f11a..dfd4f3276a6d 100644
> --- a/arch/s390/pci/pci_irq.c
> +++ b/arch/s390/pci/pci_irq.c
> @@ -296,7 +296,7 @@ int arch_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
>   		zdev->aisb = bit;
>   
>   		/* Create adapter interrupt vector */
> -		zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK);
> +		zdev->aibv = airq_iv_create(msi_vecs, AIRQ_IV_DATA | AIRQ_IV_BITLOCK, 0);
>   		if (!zdev->aibv)
>   			return -ENOMEM;
>   
> @@ -421,7 +421,7 @@ static int __init zpci_directed_irq_init(void)
>   	union zpci_sic_iib iib = {{0}};
>   	unsigned int cpu;
>   
> -	zpci_sbv = airq_iv_create(num_possible_cpus(), 0);
> +	zpci_sbv = airq_iv_create(num_possible_cpus(), 0, 0);

For a pointer use NULL? Also in other places. With the indentation fix this looks sane.