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iommu/amd: Check feature support bit before accessing MSI capability registers

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The IOMMU MMIO access to MSI capability registers is available only if
the EFR[MsiCapMmioSup] is set. Current implementation assumes this bit
is set if the EFR[XtSup] is set, which might not be the case.

Fix by checking the EFR[MsiCapMmioSup] before accessing the MSI address
low/high and MSI data registers via the MMIO.

Fixes: 6692981295 ('iommu/amd: Add support for X2APIC IOMMU interrupts')
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Suravee Suthikulpanit 2019-11-20 07:55:48 -06:00 committed by Joerg Roedel
parent 387caf0b75
commit 813071438e
2 changed files with 13 additions and 5 deletions
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17
drivers/iommu/amd_iommu_init.c
View File

@ -149,7 +149,7 @@ bool amd_iommu_dump;
bool amd_iommu_irq_remap __read_mostly;
int amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_VAPIC;
static int amd_iommu_xt_mode = IRQ_REMAP_X2APIC_MODE;
static int amd_iommu_xt_mode = IRQ_REMAP_XAPIC_MODE;
static bool amd_iommu_detected;
static bool __initdata amd_iommu_disabled;
@ -1534,8 +1534,15 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
iommu->mmio_phys_end = MMIO_CNTR_CONF_OFFSET;
if (((h->efr_reg & (0x1 << IOMMU_EFR_GASUP_SHIFT)) == 0))
amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
if (((h->efr_reg & (0x1 << IOMMU_EFR_XTSUP_SHIFT)) == 0))
amd_iommu_xt_mode = IRQ_REMAP_XAPIC_MODE;
/*
* Note: Since iommu_update_intcapxt() leverages
* the IOMMU MMIO access to MSI capability block registers
* for MSI address lo/hi/data, we need to check both
* EFR[XtSup] and EFR[MsiCapMmioSup] for x2APIC support.
*/
if ((h->efr_reg & BIT(IOMMU_EFR_XTSUP_SHIFT)) &&
(h->efr_reg & BIT(IOMMU_EFR_MSICAPMMIOSUP_SHIFT)))
amd_iommu_xt_mode = IRQ_REMAP_X2APIC_MODE;
break;
default:
return -EINVAL;
@ -1984,8 +1991,8 @@ static int iommu_init_intcapxt(struct amd_iommu *iommu)
struct irq_affinity_notify *notify = &iommu->intcapxt_notify;
/**
* IntCapXT requires XTSup=1, which can be inferred
* amd_iommu_xt_mode.
* IntCapXT requires XTSup=1 and MsiCapMmioSup=1,
* which can be inferred from amd_iommu_xt_mode.
*/
if (amd_iommu_xt_mode != IRQ_REMAP_X2APIC_MODE)
return 0;

1
drivers/iommu/amd_iommu_types.h
View File

@ -383,6 +383,7 @@
/* IOMMU Extended Feature Register (EFR) */
#define IOMMU_EFR_XTSUP_SHIFT 2
#define IOMMU_EFR_GASUP_SHIFT 7
#define IOMMU_EFR_MSICAPMMIOSUP_SHIFT 46
#define MAX_DOMAIN_ID 65536