Merge tag 'x86-irq-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 interrupt handling updates from Thomas Gleixner:
 "Add support for posted interrupts on bare metal.

  Posted interrupts is a virtualization feature which allows to inject
  interrupts directly into a guest without host interaction. The VT-d
  interrupt remapping hardware sets the bit which corresponds to the
  interrupt vector in a vector bitmap which is either used to inject the
  interrupt directly into the guest via a virtualized APIC or in case
  that the guest is scheduled out provides a host side notification
  interrupt which informs the host that an interrupt has been marked
  pending in the bitmap.

  This can be utilized on bare metal for scenarios where multiple
  devices, e.g. NVME storage, raise interrupts with a high frequency. In
  the default mode these interrupts are handles independently and
  therefore require a full roundtrip of interrupt entry/exit.

  Utilizing posted interrupts this roundtrip overhead can be avoided by
  coalescing these interrupt entries to a single entry for the posted
  interrupt notification. The notification interrupt then demultiplexes
  the pending bits in a memory based bitmap and invokes the
  corresponding device specific handlers.

  Depending on the usage scenario and device utilization throughput
  improvements between 10% and 130% have been measured.

  As this is only relevant for high end servers with multiple device
  queues per CPU attached and counterproductive for situations where
  interrupts are arriving at distinct times, the functionality is opt-in
  via a kernel command line parameter"

* tag 'x86-irq-2024-05-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/irq: Use existing helper for pending vector check
  iommu/vt-d: Enable posted mode for device MSIs
  iommu/vt-d: Make posted MSI an opt-in command line option
  x86/irq: Extend checks for pending vectors to posted interrupts
  x86/irq: Factor out common code for checking pending interrupts
  x86/irq: Install posted MSI notification handler
  x86/irq: Factor out handler invocation from common_interrupt()
  x86/irq: Set up per host CPU posted interrupt descriptors
  x86/irq: Reserve a per CPU IDT vector for posted MSIs
  x86/irq: Add a Kconfig option for posted MSI
  x86/irq: Remove bitfields in posted interrupt descriptor
  x86/irq: Unionize PID.PIR for 64bit access w/o casting
  KVM: VMX: Move posted interrupt descriptor out of VMX code

4 files changed, 6 insertions, 96 deletions

diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c
index af662312fd07..ec08fa3caf43 100644
--- a/arch/x86/kvm/vmx/posted_intr.c
+++ b/arch/x86/kvm/vmx/posted_intr.c
@@ -107,7 +107,7 @@ void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu)
 		 * handle task migration (@cpu != vcpu->cpu).
 		 */
 		new.ndst = dest;
-		new.sn = 0;
+		__pi_clear_sn(&new);
 
 		/*
 		 * Restore the notification vector; in the blocking case, the
@@ -157,7 +157,7 @@ static void pi_enable_wakeup_handler(struct kvm_vcpu *vcpu)
 		      &per_cpu(wakeup_vcpus_on_cpu, vcpu->cpu));
 	raw_spin_unlock(&per_cpu(wakeup_vcpus_on_cpu_lock, vcpu->cpu));
 
-	WARN(pi_desc->sn, "PI descriptor SN field set before blocking");
+	WARN(pi_test_sn(pi_desc), "PI descriptor SN field set before blocking");
 
 	old.control = READ_ONCE(pi_desc->control);
 	do {
diff --git a/arch/x86/kvm/vmx/posted_intr.h b/arch/x86/kvm/vmx/posted_intr.h
index 26992076552e..6b2a0226257e 100644
--- a/arch/x86/kvm/vmx/posted_intr.h
+++ b/arch/x86/kvm/vmx/posted_intr.h
@@ -1,98 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __KVM_X86_VMX_POSTED_INTR_H
 #define __KVM_X86_VMX_POSTED_INTR_H
-
-#define POSTED_INTR_ON  0
-#define POSTED_INTR_SN  1
-
-#define PID_TABLE_ENTRY_VALID 1
-
-/* Posted-Interrupt Descriptor */
-struct pi_desc {
-	u32 pir[8];     /* Posted interrupt requested */
-	union {
-		struct {
-				/* bit 256 - Outstanding Notification */
-			u16	on	: 1,
-				/* bit 257 - Suppress Notification */
-				sn	: 1,
-				/* bit 271:258 - Reserved */
-				rsvd_1	: 14;
-				/* bit 279:272 - Notification Vector */
-			u8	nv;
-				/* bit 287:280 - Reserved */
-			u8	rsvd_2;
-				/* bit 319:288 - Notification Destination */
-			u32	ndst;
-		};
-		u64 control;
-	};
-	u32 rsvd[6];
-} __aligned(64);
-
-static inline bool pi_test_and_set_on(struct pi_desc *pi_desc)
-{
-	return test_and_set_bit(POSTED_INTR_ON,
-			(unsigned long *)&pi_desc->control);
-}
-
-static inline bool pi_test_and_clear_on(struct pi_desc *pi_desc)
-{
-	return test_and_clear_bit(POSTED_INTR_ON,
-			(unsigned long *)&pi_desc->control);
-}
-
-static inline bool pi_test_and_clear_sn(struct pi_desc *pi_desc)
-{
-	return test_and_clear_bit(POSTED_INTR_SN,
-			(unsigned long *)&pi_desc->control);
-}
-
-static inline bool pi_test_and_set_pir(int vector, struct pi_desc *pi_desc)
-{
-	return test_and_set_bit(vector, (unsigned long *)pi_desc->pir);
-}
-
-static inline bool pi_is_pir_empty(struct pi_desc *pi_desc)
-{
-	return bitmap_empty((unsigned long *)pi_desc->pir, NR_VECTORS);
-}
-
-static inline void pi_set_sn(struct pi_desc *pi_desc)
-{
-	set_bit(POSTED_INTR_SN,
-		(unsigned long *)&pi_desc->control);
-}
-
-static inline void pi_set_on(struct pi_desc *pi_desc)
-{
-	set_bit(POSTED_INTR_ON,
-		(unsigned long *)&pi_desc->control);
-}
-
-static inline void pi_clear_on(struct pi_desc *pi_desc)
-{
-	clear_bit(POSTED_INTR_ON,
-		(unsigned long *)&pi_desc->control);
-}
-
-static inline void pi_clear_sn(struct pi_desc *pi_desc)
-{
-	clear_bit(POSTED_INTR_SN,
-		(unsigned long *)&pi_desc->control);
-}
-
-static inline bool pi_test_on(struct pi_desc *pi_desc)
-{
-	return test_bit(POSTED_INTR_ON,
-			(unsigned long *)&pi_desc->control);
-}
-
-static inline bool pi_test_sn(struct pi_desc *pi_desc)
-{
-	return test_bit(POSTED_INTR_SN,
-			(unsigned long *)&pi_desc->control);
-}
+#include <asm/posted_intr.h>
 
 void vmx_vcpu_pi_load(struct kvm_vcpu *vcpu, int cpu);
 void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 22411f4aff53..becefaf95cab 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -70,6 +70,7 @@
 #include "x86.h"
 #include "smm.h"
 #include "vmx_onhyperv.h"
+#include "posted_intr.h"
 
 MODULE_AUTHOR("Qumranet");
 MODULE_LICENSE("GPL");
@@ -4844,7 +4845,7 @@ static void __vmx_vcpu_reset(struct kvm_vcpu *vcpu)
 	 * or POSTED_INTR_WAKEUP_VECTOR.
 	 */
 	vmx->pi_desc.nv = POSTED_INTR_VECTOR;
-	vmx->pi_desc.sn = 1;
+	__pi_set_sn(&vmx->pi_desc);
 }
 
 static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
diff --git a/arch/x86/kvm/vmx/vmx.h b/arch/x86/kvm/vmx/vmx.h
index 90f9e4434646..7e483366b31e 100644
--- a/arch/x86/kvm/vmx/vmx.h
+++ b/arch/x86/kvm/vmx/vmx.h
@@ -7,10 +7,10 @@
 #include <asm/kvm.h>
 #include <asm/intel_pt.h>
 #include <asm/perf_event.h>
+#include <asm/posted_intr.h>
 
 #include "capabilities.h"
 #include "../kvm_cache_regs.h"
-#include "posted_intr.h"
 #include "vmcs.h"
 #include "vmx_ops.h"
 #include "../cpuid.h"