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iommu/vt-d: Don't clobber posted vCPU IRTE when host IRQ affinity changes

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Don't overwrite an IRTE that is posting IRQs to a vCPU with a posted MSI
entry if the host IRQ affinity happens to change.  If/when the IRTE is
reverted back to "host mode", it will be reconfigured as a posted MSI or
remapped entry as appropriate.

Drop the "mode" field, which doesn't differentiate between posted MSIs and
posted vCPUs, in favor of a dedicated posted_vcpu flag.  Note!  The two
posted_{msi,vcpu} flags are intentionally not mutually exclusive; an IRTE
can transition between posted MSI and posted vCPU.

Fixes: ed1e48ea43 ("iommu/vt-d: Enable posted mode for device MSIs")
Cc: stable@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20250315025135.2365846-3-seanjc@google.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Sean Christopherson 2025-03-19 10:21:00 +08:00 committed by Joerg Roedel
parent 2454823e97
commit 688124cc54
1 changed files with 15 additions and 10 deletions
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25
drivers/iommu/intel/irq_remapping.c
View File

@ -25,11 +25,6 @@
#include "../irq_remapping.h"
#include "../iommu-pages.h"
enum irq_mode {
IRQ_REMAPPING,
IRQ_POSTING,
};
struct ioapic_scope {
struct intel_iommu *iommu;
unsigned int id;
@ -49,8 +44,8 @@ struct irq_2_iommu {
u16 irte_index;
u16 sub_handle;
u8 irte_mask;
enum irq_mode mode;
bool posted_msi;
bool posted_vcpu;
};
struct intel_ir_data {
@ -138,7 +133,6 @@ static int alloc_irte(struct intel_iommu *iommu,
irq_iommu->irte_index = index;
irq_iommu->sub_handle = 0;
irq_iommu->irte_mask = mask;
irq_iommu->mode = IRQ_REMAPPING;
}
raw_spin_unlock_irqrestore(&irq_2_ir_lock, flags);
@ -193,8 +187,6 @@ static int modify_irte(struct irq_2_iommu *irq_iommu,
rc = qi_flush_iec(iommu, index, 0);
/* Update iommu mode according to the IRTE mode */
irq_iommu->mode = irte->pst ? IRQ_POSTING : IRQ_REMAPPING;
raw_spin_unlock_irqrestore(&irq_2_ir_lock, flags);
return rc;
@ -1173,9 +1165,18 @@ static void __intel_ir_reconfigure_irte(struct irq_data *irqd, bool force_host)
{
struct intel_ir_data *ir_data = irqd->chip_data;
/*
* Don't modify IRTEs for IRQs that are being posted to vCPUs if the
* host CPU affinity changes.
*/
if (ir_data->irq_2_iommu.posted_vcpu && !force_host)
return;
ir_data->irq_2_iommu.posted_vcpu = false;
if (ir_data->irq_2_iommu.posted_msi)
intel_ir_reconfigure_irte_posted(irqd);
else if (force_host || ir_data->irq_2_iommu.mode == IRQ_REMAPPING)
else
modify_irte(&ir_data->irq_2_iommu, &ir_data->irte_entry);
}
@ -1270,6 +1271,7 @@ static int intel_ir_set_vcpu_affinity(struct irq_data *data, void *info)
irte_pi.pda_h = (vcpu_pi_info->pi_desc_addr >> 32) &
~(-1UL << PDA_HIGH_BIT);
ir_data->irq_2_iommu.posted_vcpu = true;
modify_irte(&ir_data->irq_2_iommu, &irte_pi);
}
@ -1496,6 +1498,9 @@ static void intel_irq_remapping_deactivate(struct irq_domain *domain,
struct intel_ir_data *data = irq_data->chip_data;
struct irte entry;
WARN_ON_ONCE(data->irq_2_iommu.posted_vcpu);
data->irq_2_iommu.posted_vcpu = false;
memset(&entry, 0, sizeof(entry));
modify_irte(&data->irq_2_iommu, &entry);
}