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x86/irq: Remove bitfields in posted interrupt descriptor

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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
This commit is contained in:
Jacob Pan 2024-04-23 10:41:05 -07:00 committed by Thomas Gleixner
parent 4ec8fd0371
commit 2254808b53
3 changed files with 15 additions and 12 deletions
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21
arch/x86/include/asm/posted_intr.h
View File

@ -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 notifications; /* Suppress and outstanding bits */
u8 nv;
/* bit 287:280 - Reserved */
u8 rsvd_2;
/* bit 319:288 - Notification Destination */
u32 ndst;
};
u64 control;
@ -88,4 +80,15 @@ static inline bool pi_test_sn(struct pi_desc *pi_desc)
return test_bit(POSTED_INTR_SN, (unsigned long *)&pi_desc->control);
}
/* Non-atomic helpers */
static inline void __pi_set_sn(struct pi_desc *pi_desc)
{
pi_desc->notifications |= BIT(POSTED_INTR_SN);
}
static inline void __pi_clear_sn(struct pi_desc *pi_desc)
{
pi_desc->notifications &= ~BIT(POSTED_INTR_SN);
}
#endif /* _X86_POSTED_INTR_H */

4
arch/x86/kvm/vmx/posted_intr.c
View File

@ -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 {

2
arch/x86/kvm/vmx/vmx.c
View File

@ -4845,7 +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)