linux-kernel - Re: [PATCH 10/10] iommu/amd: Copy the old ir table

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 29 Sep 2015 18:11:41 +0200
From:	Joerg Roedel <joro@...tes.org>
To:	Baoquan He <bhe@...hat.com>
Cc:	iommu@...ts.linux-foundation.org, kexec@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH 10/10] iommu/amd: Copy the old ir table

On Thu, Sep 24, 2015 at 02:37:36PM +0800, Baoquan He wrote:
> Signed-off-by: Baoquan He <bhe@...hat.com>
> ---
>  drivers/iommu/amd_iommu.c | 25 +++++++++++++++++++------
>  1 file changed, 19 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
> index 1e86f4c..f4f3e63 100644
> --- a/drivers/iommu/amd_iommu.c
> +++ b/drivers/iommu/amd_iommu.c
> @@ -3683,12 +3683,25 @@ static struct irq_remap_table *get_irq_table(u16 devid, bool ioapic)
>  
>  	memset(table->table, 0, MAX_IRQS_PER_TABLE * sizeof(u32));
>  
> -	if (ioapic) {
> -		int i;
> -
> -		for (i = 0; i < 32; ++i)
> -			table->table[i] = IRTE_ALLOCATED;
> -	}
> +	if (translation_pre_enabled()) {
> +		u64 dte;
> +                u64 old_intr_virt;
> +                dte     = amd_iommu_dev_table[devid].data[2];
> +                dte &= DTE_IRQ_PHYS_ADDR_MASK;
> +                old_intr_virt = ioremap_cache(dte, MAX_IRQS_PER_TABLE * sizeof(u32));
> +                memcpy_fromio(table->table, old_intr_virt, MAX_IRQS_PER_TABLE * sizeof(u32));
> +                iounmap(old_intr_virt);
> +                iommu_flush_irt(iommu, devid);
> +        }
> +        else {
> +
> +                if (ioapic) {
> +                        int i;
> +
> +                        for (i = 0; i < 32; ++i)
> +                                table->table[i] = IRTE_ALLOCATED;
> +                }
> +        }

Is it necessary to copy the old ir tables? On AMD these tables are
per-device, so it is probably the best to handle them like the io
page-tables and just update the pointer to it in the device-table upon
interrupt initialization.


	Joerg

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/