[PATCH v2 03/13] x86/irq: Remove bitfields in posted interrupt descriptor

From: Jacob Pan
Date: Fri Apr 05 2024 - 18:27:31 EST


Mixture of bitfields and types is weird and really not intuitive, remove
bitfields and use typed data exclusively.

Link: https://lore.kernel.org/all/20240404101735.402feec8@jacob-builder/T/#mf66e34a82a48f4d8e2926b5581eff59a122de53a
Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>

---
v2:
- Replace bitfields, no more mix.
---
arch/x86/include/asm/posted_intr.h | 10 +---------
arch/x86/kvm/vmx/posted_intr.c | 4 ++--
arch/x86/kvm/vmx/vmx.c | 2 +-
3 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/arch/x86/include/asm/posted_intr.h b/arch/x86/include/asm/posted_intr.h
index acf237b2882e..c682c41d4e44 100644
--- a/arch/x86/include/asm/posted_intr.h
+++ b/arch/x86/include/asm/posted_intr.h
@@ -15,17 +15,9 @@ struct pi_desc {
};
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 */
+ u16 notif_ctrl; /* Suppress and outstanding bits */
u8 nv;
- /* bit 287:280 - Reserved */
u8 rsvd_2;
- /* bit 319:288 - Notification Destination */
u32 ndst;
};
u64 control;
diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c
index af662312fd07..592dbb765675 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;
+ new.notif_ctrl &= ~POSTED_INTR_SN;

/*
* 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_desc->notif_ctrl & POSTED_INTR_SN, "PI descriptor SN field set before blocking");

old.control = READ_ONCE(pi_desc->control);
do {
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index d94bb069bac9..50580bbfba5d 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4843,7 +4843,7 @@ 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;
+ vmx->pi_desc.notif_ctrl |= POSTED_INTR_SN;
}

static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
--
2.25.1