Re: [PATCH 05/67] iommu/amd: Return an error if vCPU affinity is set for non-vCPU IRTE
From: Sairaj Kodilkar
Date: Fri Apr 11 2025 - 13:08:40 EST
On 4/11/2025 7:35 PM, Sean Christopherson wrote:
On Fri, Apr 11, 2025, Sairaj Kodilkar wrote:
On 4/5/2025 1:08 AM, Sean Christopherson wrote:
Return -EINVAL instead of success if amd_ir_set_vcpu_affinity() is
invoked without use_vapic; lying to KVM about whether or not the IRTE was
configured to post IRQs is all kinds of bad.
Fixes: d98de49a53e4 ("iommu/amd: Enable vAPIC interrupt remapping mode by default")
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
drivers/iommu/amd/iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index cd5116d8c3b2..b3a01b7757ee 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -3850,7 +3850,7 @@ static int amd_ir_set_vcpu_affinity(struct irq_data *data, void *vcpu_info)
* we should not modify the IRTE
*/
if (!dev_data || !dev_data->use_vapic)
- return 0;
+ return -EINVAL;
Hi Sean,
you can update following functions as well to return error when
IOMMU is using legacy interrupt mode.
1. amd_iommu_update_ga
2. amd_iommu_activate_guest_mode
3. amd_iommu_deactivate_guest_mode
Heh, I'm well aware, and this series gets there eventually (the end product WARNs
and returns an error in all three functions). I fixed amd_ir_set_vcpu_affinity()
early in the series because it's the initial API that KVM will use to configure
an IRTE for posting to a vCPU. I.e. to reach the other helpers, KVM would need
to ignore the error returned by amd_ir_set_vcpu_affinity().
Ohh sorry about that. Since I was reviewing patches sequentially, I did
come across those changes.
Regards
Sairaj Kodilkar
Currently these functions return 0 to the kvm layer when they fail to
set the IRTE.
Regards
Sairaj Kodilkar