From: Oliver Upton <oliver.upton@linux.dev>
To: kvmarm@lists.linux.dev
Cc: kvm@vger.kernel.org, Marc Zyngier <maz@kernel.org>,
James Morse <james.morse@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
linux-kernel@vger.kernel.org,
Oliver Upton <oliver.upton@linux.dev>
Subject: [PATCH v2 02/23] KVM: arm64: vgic: Store LPIs in an xarray
Date: Tue, 13 Feb 2024 09:32:39 +0000 [thread overview]
Message-ID: <20240213093250.3960069-3-oliver.upton@linux.dev> (raw)
In-Reply-To: <20240213093250.3960069-1-oliver.upton@linux.dev>
Using a linked-list for LPIs is less than ideal as it of course requires
iterative searches to find a particular entry. An xarray is a better
data structure for this use case, as it provides faster searches and can
still handle a potentially sparse range of INTID allocations.
Start by storing LPIs in an xarray, punting usage of the xarray to a
subsequent change.
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
arch/arm64/kvm/vgic/vgic-init.c | 3 +++
arch/arm64/kvm/vgic/vgic-its.c | 16 ++++++++++++++++
arch/arm64/kvm/vgic/vgic.c | 1 +
include/kvm/arm_vgic.h | 2 ++
4 files changed, 22 insertions(+)
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c
index e949e1d0fd9f..411719053107 100644
--- a/arch/arm64/kvm/vgic/vgic-init.c
+++ b/arch/arm64/kvm/vgic/vgic-init.c
@@ -56,6 +56,7 @@ void kvm_vgic_early_init(struct kvm *kvm)
INIT_LIST_HEAD(&dist->lpi_list_head);
INIT_LIST_HEAD(&dist->lpi_translation_cache);
raw_spin_lock_init(&dist->lpi_list_lock);
+ xa_init_flags(&dist->lpi_xa, XA_FLAGS_LOCK_IRQ);
}
/* CREATION */
@@ -366,6 +367,8 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
if (vgic_supports_direct_msis(kvm))
vgic_v4_teardown(kvm);
+
+ xa_destroy(&dist->lpi_xa);
}
static void __kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c
index 59179268ac2d..0265cd1f2d6e 100644
--- a/arch/arm64/kvm/vgic/vgic-its.c
+++ b/arch/arm64/kvm/vgic/vgic-its.c
@@ -53,6 +53,12 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,
if (!irq)
return ERR_PTR(-ENOMEM);
+ ret = xa_reserve_irq(&dist->lpi_xa, intid, GFP_KERNEL_ACCOUNT);
+ if (ret) {
+ kfree(irq);
+ return ERR_PTR(ret);
+ }
+
INIT_LIST_HEAD(&irq->lpi_list);
INIT_LIST_HEAD(&irq->ap_list);
raw_spin_lock_init(&irq->irq_lock);
@@ -87,10 +93,20 @@ static struct vgic_irq *vgic_add_lpi(struct kvm *kvm, u32 intid,
goto out_unlock;
}
+ ret = xa_err(xa_store(&dist->lpi_xa, intid, irq, 0));
+ if (ret) {
+ xa_release(&dist->lpi_xa, intid);
+ kfree(irq);
+ goto out_unlock;
+ }
+
list_add_tail(&irq->lpi_list, &dist->lpi_list_head);
dist->lpi_list_count++;
out_unlock:
+ if (ret)
+ return ERR_PTR(ret);
+
raw_spin_unlock_irqrestore(&dist->lpi_list_lock, flags);
/*
diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index db2a95762b1b..c126014f8395 100644
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -131,6 +131,7 @@ void __vgic_put_lpi_locked(struct kvm *kvm, struct vgic_irq *irq)
return;
list_del(&irq->lpi_list);
+ xa_erase(&dist->lpi_xa, irq->intid);
dist->lpi_list_count--;
kfree(irq);
diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
index 8cc38e836f54..795b35656b54 100644
--- a/include/kvm/arm_vgic.h
+++ b/include/kvm/arm_vgic.h
@@ -13,6 +13,7 @@
#include <linux/spinlock.h>
#include <linux/static_key.h>
#include <linux/types.h>
+#include <linux/xarray.h>
#include <kvm/iodev.h>
#include <linux/list.h>
#include <linux/jump_label.h>
@@ -275,6 +276,7 @@ struct vgic_dist {
/* Protects the lpi_list and the count value below. */
raw_spinlock_t lpi_list_lock;
+ struct xarray lpi_xa;
struct list_head lpi_list_head;
int lpi_list_count;
--
2.43.0.687.g38aa6559b0-goog
next prev parent reply other threads:[~2024-02-13 9:33 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-13 9:32 [PATCH v2 00/23] KVM: arm64: Improvements to LPI injection Oliver Upton
2024-02-13 9:32 ` [PATCH v2 01/23] KVM: arm64: Add tracepoints + stats for LPI cache effectiveness Oliver Upton
2024-02-14 15:55 ` Marc Zyngier
2024-02-13 9:32 ` Oliver Upton [this message]
2024-02-13 21:52 ` [PATCH v2 02/23] KVM: arm64: vgic: Store LPIs in an xarray Oliver Upton
2024-02-13 9:32 ` [PATCH v2 03/23] KVM: arm64: vgic: Use xarray to find LPI in vgic_get_lpi() Oliver Upton
2024-02-13 9:32 ` [PATCH v2 04/23] KVM: arm64: vgic-v3: Iterate the xarray to find pending LPIs Oliver Upton
2024-02-13 9:32 ` [PATCH v2 05/23] KVM: arm64: vgic-its: Walk the LPI xarray in vgic_copy_lpi_list() Oliver Upton
2024-02-13 9:32 ` [PATCH v2 06/23] KVM: arm64: vgic: Get rid of the LPI linked-list Oliver Upton
2024-02-13 9:32 ` [PATCH v2 07/23] KVM: arm64: vgic: Use atomics to count LPIs Oliver Upton
2024-02-14 16:47 ` Marc Zyngier
2024-02-14 18:32 ` Oliver Upton
2024-02-14 20:01 ` Marc Zyngier
2024-02-14 23:01 ` Oliver Upton
2024-02-15 9:44 ` Marc Zyngier
2024-02-13 9:32 ` [PATCH v2 08/23] KVM: arm64: vgic: Free LPI vgic_irq structs in an RCU-safe manner Oliver Upton
2024-02-13 9:32 ` [PATCH v2 09/23] KVM: arm64: vgic: Rely on RCU protection in vgic_get_lpi() Oliver Upton
2024-02-13 9:32 ` [PATCH v2 10/23] KVM: arm64: vgic: Ensure the irq refcount is nonzero when taking a ref Oliver Upton
2024-02-13 9:32 ` [PATCH v2 11/23] KVM: arm64: vgic: Don't acquire the lpi_list_lock in vgic_put_irq() Oliver Upton
2024-02-13 9:32 ` [PATCH v2 12/23] KVM: arm64: vgic-its: Lazily allocate LPI translation cache Oliver Upton
2024-02-13 9:32 ` [PATCH v2 13/23] KVM: arm64: vgic-its: Pick cache victim based on usage count Oliver Upton
2024-02-13 9:37 ` [PATCH v2 14/23] KVM: arm64: vgic-its: Protect cached vgic_irq pointers with RCU Oliver Upton
2024-02-13 9:39 ` [PATCH v2 15/23] KVM: arm64: vgic-its: Treat the LPI translation cache as an rculist Oliver Upton
2024-02-13 9:40 ` [PATCH v2 16/23] KVM: arm64: vgic-its: Rely on RCU to protect translation cache reads Oliver Upton
2024-02-13 9:40 ` [PATCH v2 17/23] KVM: selftests: Align with kernel's GIC definitions Oliver Upton
2024-02-13 9:40 ` [PATCH v2 18/23] KVM: selftests: Standardise layout of GIC frames Oliver Upton
2024-02-13 9:41 ` [PATCH v2 19/23] KVM: selftests: Add a minimal library for interacting with an ITS Oliver Upton
2024-02-14 17:32 ` Marc Zyngier
2024-02-14 19:00 ` Oliver Upton
2024-02-14 20:09 ` Marc Zyngier
2024-02-14 20:55 ` Oliver Upton
2024-02-14 21:06 ` Oliver Upton
2024-02-13 9:41 ` [PATCH v2 20/23] KVM: selftests: Add helper for enabling LPIs on a redistributor Oliver Upton
2024-02-13 9:42 ` [PATCH v2 21/23] KVM: selftests: Use MPIDR_HWID_BITMASK from cputype.h Oliver Upton
2024-02-13 9:43 ` [PATCH v2 22/23] KVM: selftests: Hack in support for aligned page allocations Oliver Upton
2024-02-13 9:43 ` [PATCH v2 23/23] KVM: selftests: Add stress test for LPI injection Oliver Upton
2024-02-13 20:12 ` [PATCH v2 00/23] KVM: arm64: Improvements to " Oliver Upton
2024-02-14 17:43 ` Marc Zyngier
2024-02-14 18:40 ` Oliver Upton
2024-02-15 15:37 ` Marc Zyngier
2024-02-15 20:15 ` Oliver Upton
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