| Message ID | 20250311152754.63912-1-roger.pau@citrix.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v5,1/3] x86/vmx: fix posted interrupts usage of msi_desc->msg field | expand |
On 11.03.2025 16:27, Roger Pau Monne wrote: > The current usage of msi_desc->msg in vmx_pi_update_irte() will make the > field contain a translated MSI message, instead of the expected > untranslated one. This breaks dump_msi(), that use the data in > msi_desc->msg to print the interrupt details. > > Fix this by introducing a dummy local msi_msg, and use it with > iommu_update_ire_from_msi(). vmx_pi_update_irte() relies on the MSI > message not changing, so there's no need to propagate the resulting msi_msg > to the hardware, and the contents can be ignored. > > Additionally add a comment to clarify that msi_desc->msg must always > contain the untranslated MSI message. > > Fixes: a5e25908d18d ('VT-d: introduce new fields in msi_desc to track binding with guest interrupt') > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index 0241303b4bf4..23b7ecd77f85 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -396,6 +396,7 @@ static int cf_check vmx_pi_update_irte(const struct vcpu *v, const struct pi_desc *pi_desc = v ? &v->arch.hvm.vmx.pi_desc : NULL; struct irq_desc *desc; struct msi_desc *msi_desc; + struct msi_msg msg; int rc; desc = pirq_spin_lock_irq_desc(pirq, NULL); @@ -410,12 +411,13 @@ static int cf_check vmx_pi_update_irte(const struct vcpu *v, } msi_desc->pi_desc = pi_desc; msi_desc->gvec = gvec; + msg = msi_desc->msg; spin_unlock_irq(&desc->lock); ASSERT_PDEV_LIST_IS_READ_LOCKED(msi_desc->dev->domain); - return iommu_update_ire_from_msi(msi_desc, &msi_desc->msg); + return iommu_update_ire_from_msi(msi_desc, &msg); unlock_out: spin_unlock_irq(&desc->lock); diff --git a/xen/arch/x86/include/asm/msi.h b/xen/arch/x86/include/asm/msi.h index 378b85ee947b..975d0f26b35d 100644 --- a/xen/arch/x86/include/asm/msi.h +++ b/xen/arch/x86/include/asm/msi.h @@ -124,7 +124,7 @@ struct msi_desc { int irq; int remap_index; /* index in interrupt remapping table */ - struct msi_msg msg; /* Last set MSI message */ + struct msi_msg msg; /* Last set MSI message (untranslated) */ }; /*
The current usage of msi_desc->msg in vmx_pi_update_irte() will make the field contain a translated MSI message, instead of the expected untranslated one. This breaks dump_msi(), that use the data in msi_desc->msg to print the interrupt details. Fix this by introducing a dummy local msi_msg, and use it with iommu_update_ire_from_msi(). vmx_pi_update_irte() relies on the MSI message not changing, so there's no need to propagate the resulting msi_msg to the hardware, and the contents can be ignored. Additionally add a comment to clarify that msi_desc->msg must always contain the untranslated MSI message. Fixes: a5e25908d18d ('VT-d: introduce new fields in msi_desc to track binding with guest interrupt') Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> --- Changes since v4: - Initialize the local msi_msg with the contents of msi_desc->msg. Changes since v3: - New in this version. --- xen/arch/x86/hvm/vmx/vmx.c | 4 +++- xen/arch/x86/include/asm/msi.h | 2 +- 2 files changed, 4 insertions(+), 2 deletions(-)