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path: root/arch/x86/include/asm/posted_intr.h
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2025-04-24x86/irq: KVM: Add helper for harvesting PIR to deduplicate KVM and posted MSIsSean Christopherson
Now that posted MSI and KVM harvesting of PIR is identical, extract the code (and posted MSI's wonderful comment) to a common helper. No functional change intended. Link: https://lore.kernel.org/r/20250401163447.846608-9-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-04-24x86/irq: KVM: Track PIR bitmap as an "unsigned long" arraySean Christopherson
Track the PIR bitmap in posted interrupt descriptor structures as an array of unsigned longs instead of using unionized arrays for KVM (u32s) versus IRQ management (u64s). In practice, because the non-KVM usage is (sanely) restricted to 64-bit kernels, all existing usage of the u64 variant is already working with unsigned longs. Using "unsigned long" for the array will allow reworking KVM's processing of the bitmap to read/write in 64-bit chunks on 64-bit kernels, i.e. will allow optimizing KVM by reducing the number of atomic accesses to PIR. Opportunstically replace the open coded literals in the posted MSIs code with the appropriate macro. Deliberately don't use ARRAY_SIZE() in the for-loops, even though it would be cleaner from a certain perspective, in anticipation of decoupling the processing from the array declaration. No functional change intended. Link: https://lore.kernel.org/r/20250401163447.846608-5-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com>
2025-03-14KVM: TDX: Wait lapic expire when timer IRQ was injectedIsaku Yamahata
Call kvm_wait_lapic_expire() when POSTED_INTR_ON is set and the vector for LVTT is set in PIR before TD entry. KVM always assumes a timer IRQ was injected if APIC state is protected. For TDX guest, APIC state is protected and KVM injects timer IRQ via posted interrupt. To avoid unnecessary wait calls, only call kvm_wait_lapic_expire() when a timer IRQ was injected, i.e., POSTED_INTR_ON is set and the vector for LVTT is set in PIR. Add a helper to test PIR. Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com> Co-developed-by: Binbin Wu <binbin.wu@linux.intel.com> Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com> Message-ID: <20250222014757.897978-7-binbin.wu@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-04-30x86/irq: Extend checks for pending vectors to posted interruptsJacob Pan
During interrupt affinity change, it is possible to have interrupts delivered to the old CPU after the affinity has changed to the new one. To prevent lost interrupts, local APIC IRR is checked on the old CPU. Similar checks must be done for posted MSIs given the same reason. Consider the following scenario: Device system agent iommu memory CPU/LAPIC 1 FEEX_XXXX 2 Interrupt request 3 Fetch IRTE -> 4 ->Atomic Swap PID.PIR(vec) Push to Global Observable(GO) 5 if (ON*) done;* else 6 send a notification -> * ON: outstanding notification, 1 will suppress new notifications If the affinity change happens between 3 and 5 in the IOMMU, the old CPU's posted interrupt request (PIR) could have the pending bit set for the vector being moved. Add a helper function to check individual vector status. Then use the helper to check for pending interrupts on the source CPU's PID. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240423174114.526704-11-jacob.jun.pan@linux.intel.com
2024-04-30x86/irq: Set up per host CPU posted interrupt descriptorsJacob Pan
To support posted MSIs, create a posted interrupt descriptor (PID) for each host CPU. Later on, when setting up interrupt affinity, the IOMMU's interrupt remapping table entry (IRTE) will point to the physical address of the matching CPU's PID. Each PID is initialized with the owner CPU's physical APICID as the destination. Originally-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240423174114.526704-7-jacob.jun.pan@linux.intel.com
2024-04-30x86/irq: Remove bitfields in posted interrupt descriptorJacob Pan
Mixture of bitfields and types is weird and really not intuitive, remove bitfields and use typed data exclusively. Bitfields often result in inferior machine code. Suggested-by: Sean Christopherson <seanjc@google.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240423174114.526704-4-jacob.jun.pan@linux.intel.com Link: https://lore.kernel.org/all/20240404101735.402feec8@jacob-builder/T/#mf66e34a82a48f4d8e2926b5581eff59a122de53a
2024-04-30x86/irq: Unionize PID.PIR for 64bit access w/o castingJacob Pan
Make the PIR field into u64 such that atomic xchg64 can be used without ugly casting. Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240423174114.526704-3-jacob.jun.pan@linux.intel.com
2024-04-30KVM: VMX: Move posted interrupt descriptor out of VMX codeJacob Pan
To prepare native usage of posted interrupts, move the PID declarations out of VMX code such that they can be shared. Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Sean Christopherson <seanjc@google.com> Link: https://lore.kernel.org/r/20240423174114.526704-2-jacob.jun.pan@linux.intel.com