* [PATCH 1/2] KVM: arm/arm64: Fix reference to uninitialised VGIC
2016-02-11 15:59 [PULL] KVM/ARM fixes for 4.5-rc4 Marc Zyngier
@ 2016-02-11 15:59 ` Marc Zyngier
2016-02-11 15:59 ` [PATCH 2/2] arm64: KVM: Configure TCR_EL2.PS at runtime Marc Zyngier
2016-02-11 21:47 ` [PULL] KVM/ARM fixes for 4.5-rc4 Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Marc Zyngier @ 2016-02-11 15:59 UTC (permalink / raw)
To: linux-arm-kernel
From: Andre Przywara <andre.przywara@arm.com>
Commit 4b4b4512da2a ("arm/arm64: KVM: Rework the arch timer to use
level-triggered semantics") brought the virtual architected timer
closer to the VGIC. There is one occasion were we don't properly
check for the VGIC actually having been initialized before, but
instead go on to check the active state of some IRQ number.
If userland hasn't instantiated a virtual GIC, we end up with a
kernel NULL pointer dereference:
=========
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = ffffffc9745c5000
[00000000] *pgd=00000009f631e003, *pud=00000009f631e003, *pmd=0000000000000000
Internal error: Oops: 96000006 [#2] PREEMPT SMP
Modules linked in:
CPU: 0 PID: 2144 Comm: kvm_simplest-ar Tainted: G D 4.5.0-rc2+ #1300
Hardware name: ARM Juno development board (r1) (DT)
task: ffffffc976da8000 ti: ffffffc976e28000 task.ti: ffffffc976e28000
PC is at vgic_bitmap_get_irq_val+0x78/0x90
LR is at kvm_vgic_map_is_active+0xac/0xc8
pc : [<ffffffc0000b7e28>] lr : [<ffffffc0000b972c>] pstate: 20000145
....
=========
Fix this by bailing out early of kvm_timer_flush_hwstate() if we don't
have a VGIC at all.
Reported-by: Cosmin Gorgovan <cosmin@linux-geek.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: <stable@vger.kernel.org> # 4.4.x
---
virt/kvm/arm/arch_timer.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c
index 69bca18..ea60646 100644
--- a/virt/kvm/arm/arch_timer.c
+++ b/virt/kvm/arm/arch_timer.c
@@ -143,7 +143,7 @@ static void kvm_timer_update_irq(struct kvm_vcpu *vcpu, bool new_level)
* Check if there was a change in the timer state (should we raise or lower
* the line level to the GIC).
*/
-static void kvm_timer_update_state(struct kvm_vcpu *vcpu)
+static int kvm_timer_update_state(struct kvm_vcpu *vcpu)
{
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
@@ -154,10 +154,12 @@ static void kvm_timer_update_state(struct kvm_vcpu *vcpu)
* until we call this function from kvm_timer_flush_hwstate.
*/
if (!vgic_initialized(vcpu->kvm))
- return;
+ return -ENODEV;
if (kvm_timer_should_fire(vcpu) != timer->irq.level)
kvm_timer_update_irq(vcpu, !timer->irq.level);
+
+ return 0;
}
/*
@@ -218,7 +220,8 @@ void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu)
bool phys_active;
int ret;
- kvm_timer_update_state(vcpu);
+ if (kvm_timer_update_state(vcpu))
+ return;
/*
* If we enter the guest with the virtual input level to the VGIC
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH 2/2] arm64: KVM: Configure TCR_EL2.PS at runtime
2016-02-11 15:59 [PULL] KVM/ARM fixes for 4.5-rc4 Marc Zyngier
2016-02-11 15:59 ` [PATCH 1/2] KVM: arm/arm64: Fix reference to uninitialised VGIC Marc Zyngier
@ 2016-02-11 15:59 ` Marc Zyngier
2016-02-11 21:47 ` [PULL] KVM/ARM fixes for 4.5-rc4 Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Marc Zyngier @ 2016-02-11 15:59 UTC (permalink / raw)
To: linux-arm-kernel
From: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
Setting TCR_EL2.PS to 40 bits is wrong on systems with less that
less than 40 bits of physical addresses. and breaks KVM on systems
where the RAM is above 40 bits.
This patch uses ID_AA64MMFR0_EL1.PARange to set TCR_EL2.PS dynamically,
just like we already do for VTCR_EL2.PS.
[Marc: rewrote commit message, patch tidy up]
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
arch/arm64/include/asm/kvm_arm.h | 2 --
arch/arm64/kvm/hyp-init.S | 12 +++++++-----
2 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index bef6e92..d201d4b 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -107,8 +107,6 @@
#define TCR_EL2_MASK (TCR_EL2_TG0 | TCR_EL2_SH0 | \
TCR_EL2_ORGN0 | TCR_EL2_IRGN0 | TCR_EL2_T0SZ)
-#define TCR_EL2_FLAGS (TCR_EL2_RES1 | TCR_EL2_PS_40B)
-
/* VTCR_EL2 Registers bits */
#define VTCR_EL2_RES1 (1 << 31)
#define VTCR_EL2_PS_MASK (7 << 16)
diff --git a/arch/arm64/kvm/hyp-init.S b/arch/arm64/kvm/hyp-init.S
index 3e568dc..d073b5a 100644
--- a/arch/arm64/kvm/hyp-init.S
+++ b/arch/arm64/kvm/hyp-init.S
@@ -64,7 +64,7 @@ __do_hyp_init:
mrs x4, tcr_el1
ldr x5, =TCR_EL2_MASK
and x4, x4, x5
- ldr x5, =TCR_EL2_FLAGS
+ mov x5, #TCR_EL2_RES1
orr x4, x4, x5
#ifndef CONFIG_ARM64_VA_BITS_48
@@ -85,15 +85,17 @@ __do_hyp_init:
ldr_l x5, idmap_t0sz
bfi x4, x5, TCR_T0SZ_OFFSET, TCR_TxSZ_WIDTH
#endif
- msr tcr_el2, x4
-
- ldr x4, =VTCR_EL2_FLAGS
/*
* Read the PARange bits from ID_AA64MMFR0_EL1 and set the PS bits in
- * VTCR_EL2.
+ * TCR_EL2 and VTCR_EL2.
*/
mrs x5, ID_AA64MMFR0_EL1
bfi x4, x5, #16, #3
+
+ msr tcr_el2, x4
+
+ ldr x4, =VTCR_EL2_FLAGS
+ bfi x4, x5, #16, #3
/*
* Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS bit in
* VTCR_EL2.
--
2.1.4
^ permalink raw reply related [flat|nested] 4+ messages in thread