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From: "Chen, Yian" <yian.chen@intel.com>
To: Barret Rhoden <brho@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Joerg Roedel <joro@8bytes.org>,
	Sohil Mehta <sohil.mehta@intel.com>
Cc: linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org,
	x86@kernel.org
Subject: Re: [PATCH v2 2/2] iommu/vt-d: skip invalid RMRR entries
Date: Fri, 10 Jan 2020 11:27:02 -0800	[thread overview]
Message-ID: <572361a3-b5ae-6717-307c-e0f14d7930cd@intel.com> (raw)
In-Reply-To: <20200107191610.178185-3-brho@google.com>

Hi Barret,

this looks good.

thanks
Yian

On 1/7/2020 11:16 AM, Barret Rhoden wrote:
> The VT-d docs specify requirements for the RMRR entries base and end
> (called 'Limit' in the docs) addresses.
>
> This commit will cause the DMAR processing to skip any RMRR entries that
> do not meet these requirements and mark the firmware as tainted, since
> the firmware is giving us junk.
>
> Signed-off-by: Barret Rhoden <brho@google.com>
> ---
>   drivers/iommu/intel-iommu.c | 14 +++++++++++++-
>   1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index a8bb458845bc..32c3c6338a3d 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -4315,13 +4315,25 @@ static void __init init_iommu_pm_ops(void)
>   static inline void init_iommu_pm_ops(void) {}
>   #endif	/* CONFIG_PM */
>   
> +static int rmrr_validity_check(struct acpi_dmar_reserved_memory *rmrr)
> +{
> +	if ((rmrr->base_address & PAGE_MASK) ||
> +	    (rmrr->end_address <= rmrr->base_address) ||
> +	    ((rmrr->end_address - rmrr->base_address + 1) & PAGE_MASK)) {
> +		pr_err(FW_BUG "Broken RMRR base: %#018Lx end: %#018Lx\n",
> +		       rmrr->base_address, rmrr->end_address);
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
>   int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
>   {
>   	struct acpi_dmar_reserved_memory *rmrr;
>   	struct dmar_rmrr_unit *rmrru;
>   
>   	rmrr = (struct acpi_dmar_reserved_memory *)header;
> -	if (arch_rmrr_sanity_check(rmrr)) {
> +	if (rmrr_validity_check(rmrr) || arch_rmrr_sanity_check(rmrr)) {
>   		WARN_TAINT(1, TAINT_FIRMWARE_WORKAROUND,
>   			   "Your BIOS is broken; bad RMRR [%#018Lx-%#018Lx]\n"
>   			   "BIOS vendor: %s; Ver: %s; Product Version: %s\n",


WARNING: multiple messages have this Message-ID (diff)
From: "Chen, Yian" <yian.chen@intel.com>
To: Barret Rhoden <brho@google.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	David Woodhouse <dwmw2@infradead.org>,
	Joerg Roedel <joro@8bytes.org>,
	Sohil Mehta <sohil.mehta@intel.com>
Cc: iommu@lists.linux-foundation.org, x86@kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 2/2] iommu/vt-d: skip invalid RMRR entries
Date: Fri, 10 Jan 2020 11:27:02 -0800	[thread overview]
Message-ID: <572361a3-b5ae-6717-307c-e0f14d7930cd@intel.com> (raw)
In-Reply-To: <20200107191610.178185-3-brho@google.com>

Hi Barret,

this looks good.

thanks
Yian

On 1/7/2020 11:16 AM, Barret Rhoden wrote:
> The VT-d docs specify requirements for the RMRR entries base and end
> (called 'Limit' in the docs) addresses.
>
> This commit will cause the DMAR processing to skip any RMRR entries that
> do not meet these requirements and mark the firmware as tainted, since
> the firmware is giving us junk.
>
> Signed-off-by: Barret Rhoden <brho@google.com>
> ---
>   drivers/iommu/intel-iommu.c | 14 +++++++++++++-
>   1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
> index a8bb458845bc..32c3c6338a3d 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -4315,13 +4315,25 @@ static void __init init_iommu_pm_ops(void)
>   static inline void init_iommu_pm_ops(void) {}
>   #endif	/* CONFIG_PM */
>   
> +static int rmrr_validity_check(struct acpi_dmar_reserved_memory *rmrr)
> +{
> +	if ((rmrr->base_address & PAGE_MASK) ||
> +	    (rmrr->end_address <= rmrr->base_address) ||
> +	    ((rmrr->end_address - rmrr->base_address + 1) & PAGE_MASK)) {
> +		pr_err(FW_BUG "Broken RMRR base: %#018Lx end: %#018Lx\n",
> +		       rmrr->base_address, rmrr->end_address);
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
>   int __init dmar_parse_one_rmrr(struct acpi_dmar_header *header, void *arg)
>   {
>   	struct acpi_dmar_reserved_memory *rmrr;
>   	struct dmar_rmrr_unit *rmrru;
>   
>   	rmrr = (struct acpi_dmar_reserved_memory *)header;
> -	if (arch_rmrr_sanity_check(rmrr)) {
> +	if (rmrr_validity_check(rmrr) || arch_rmrr_sanity_check(rmrr)) {
>   		WARN_TAINT(1, TAINT_FIRMWARE_WORKAROUND,
>   			   "Your BIOS is broken; bad RMRR [%#018Lx-%#018Lx]\n"
>   			   "BIOS vendor: %s; Ver: %s; Product Version: %s\n",

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
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  parent reply	other threads:[~2020-01-10 19:27 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-07 19:16 [PATCH v2 0/2] iommu/vt-d bad RMRR workarounds Barret Rhoden
2020-01-07 19:16 ` Barret Rhoden via iommu
2020-01-07 19:16 ` [PATCH v2 1/2] iommu/vt-d: skip RMRR entries that fail the sanity check Barret Rhoden
2020-01-07 19:16   ` Barret Rhoden via iommu
2020-01-07 19:16 ` [PATCH v2 2/2] iommu/vt-d: skip invalid RMRR entries Barret Rhoden
2020-01-07 19:16   ` Barret Rhoden via iommu
2020-01-08  1:27   ` Lu Baolu
2020-01-08  1:27     ` Lu Baolu
2020-01-08 17:35     ` Barret Rhoden
2020-01-08 17:35       ` Barret Rhoden via iommu
2020-01-10 19:27   ` Chen, Yian [this message]
2020-01-10 19:27     ` Chen, Yian

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