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From: Marc Zyngier <maz@kernel.org>
To: kvmarm@lists.linux.dev, kvm@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org
Cc: James Morse <james.morse@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>,
	Oliver Upton <oliver.upton@linux.dev>,
	Zenghui Yu <yuzenghui@huawei.com>,
	Ricardo Koller <ricarkol@google.com>,
	Simon Veith <sveith@amazon.de>,
	Reiji Watanabe <reijiw@google.com>,
	Colton Lewis <coltonlewis@google.com>,
	Joey Gouly <joey.gouly@arm.com>,
	dwmw2@infradead.org
Subject: [PATCH v2 15/19] KVM: arm64: nv: timers: Add a per-timer, per-vcpu offset
Date: Mon, 13 Mar 2023 12:48:33 +0000	[thread overview]
Message-ID: <20230313124837.2264882-16-maz@kernel.org> (raw)
In-Reply-To: <20230313124837.2264882-1-maz@kernel.org>

Being able to set a global offset isn't enough.

With NV, we also need to a per-vcpu, per-timer offset (for example,
CNTVCT_EL0 being offset by CNTVOFF_EL2).

Use a similar method as the VM-wide offset to have a timer point
to the shadow register that contains the offset value.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/arch_timer.c  | 13 ++++++++++---
 include/kvm/arm_arch_timer.h |  5 +++++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/arch_timer.c b/arch/arm64/kvm/arch_timer.c
index 11047b3dfb5b..9666e0d0423e 100644
--- a/arch/arm64/kvm/arch_timer.c
+++ b/arch/arm64/kvm/arch_timer.c
@@ -89,10 +89,17 @@ u64 timer_get_cval(struct arch_timer_context *ctxt)
 
 static u64 timer_get_offset(struct arch_timer_context *ctxt)
 {
-	if (ctxt && ctxt->offset.vm_offset)
-		return *ctxt->offset.vm_offset;
+	u64 offset = 0;
 
-	return 0;
+	if (!ctxt)
+		return 0;
+
+	if (ctxt->offset.vm_offset)
+		offset += *ctxt->offset.vm_offset;
+	if (ctxt->offset.vcpu_offset)
+		offset += *ctxt->offset.vcpu_offset;
+
+	return offset;
 }
 
 static void timer_set_ctl(struct arch_timer_context *ctxt, u32 ctl)
diff --git a/include/kvm/arm_arch_timer.h b/include/kvm/arm_arch_timer.h
index f093ea9f540d..209da0c2ac9f 100644
--- a/include/kvm/arm_arch_timer.h
+++ b/include/kvm/arm_arch_timer.h
@@ -29,6 +29,11 @@ struct arch_timer_offset {
 	 * structure. If NULL, assume a zero offset.
 	 */
 	u64	*vm_offset;
+	/*
+	 * If set, pointer to one of the offsets in the vcpu's sysreg
+	 * array. If NULL, assume a zero offset.
+	 */
+	u64	*vcpu_offset;
 };
 
 struct arch_timer_vm_data {
-- 
2.34.1


  parent reply	other threads:[~2023-03-13 13:10 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-13 12:48 [PATCH v2 00/19] KVM: arm64: Rework timer offsetting for fun and profit Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 01/19] KVM: arm64: timers: Convert per-vcpu virtual offset to a global value Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 02/19] KVM: arm64: timers: Use a per-vcpu, per-timer accumulator for fractional ns Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 03/19] arm64: Add CNTPOFF_EL2 register definition Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 04/19] arm64: Add HAS_ECV_CNTPOFF capability Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 05/19] KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 06/19] KVM: arm64: timers: Allow physical offset without CNTPOFF_EL2 Marc Zyngier
2023-03-13 16:43   ` Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 07/19] KVM: arm64: Expose {un,}lock_all_vcpus() to the reset of KVM Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 08/19] KVM: arm64: timers: Allow userspace to set the global counter offset Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 09/19] KVM: arm64: timers: Allow save/restoring of the physical timer Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 10/19] KVM: arm64: timers: Rationalise per-vcpu timer init Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 11/19] KVM: arm64: timers: Abstract per-timer IRQ access Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 12/19] KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 13/19] KVM: arm64: Abstract the number of valid timers per vcpu Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 14/19] KVM: arm64: Document KVM_ARM_SET_CNT_OFFSETS and co Marc Zyngier
2023-03-13 12:48 ` Marc Zyngier [this message]
2023-03-13 12:48 ` [PATCH v2 16/19] KVM: arm64: nv: timers: Support hyp timer emulation Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 17/19] KVM: arm64: selftests: Add physical timer registers to the sysreg list Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 18/19] KVM: arm64: selftests: Augment existing timer test to handle variable offset Marc Zyngier
2023-03-13 12:48 ` [PATCH v2 19/19] KVM: arm64: selftests: Deal with spurious timer interrupts Marc Zyngier
2023-03-23 22:19 ` [PATCH v2 00/19] KVM: arm64: Rework timer offsetting for fun and profit Colton Lewis
2023-03-23 22:54   ` Marc Zyngier

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