[PULL 0/2] KVM/ARM Fixes for v4.6-rc2

[PULL 0/2] KVM/ARM Fixes for v4.6-rc2

[Christoffer Dall]

Hi Paolo,

The following changes since commit f55532a0c0b8bb6148f4e07853b876ef73bc69ca:

  Linux 4.6-rc1 (2016-03-26 16:03:24 -0700)

are available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git tags/kvm-arm-for-4.6-rc2

for you to fetch changes up to 5f5560b1c5f3a80e91c6babb2da34a51943bbdec:

  arm64: KVM: Register CPU notifiers when the kernel runs at HYP (2016-03-31 10:27:28 +0200)

The pull contains two small patches that fix a bug that corrupts stage-2
translationson 16-bit VMID equipped systems and fixCPU PM and Hotplug after
the EL2 init code has been moved to C.

Thanks,
-Christoffer

---

James Morse (1):
      arm64: KVM: Register CPU notifiers when the kernel runs at HYP

Suzuki K Poulose (1):
      arm64: kvm: 4.6-rc1: Fix VTCR_EL2 VS setting

 arch/arm/kvm/arm.c               | 52 +++++++++++++++++++++++++---------------
 arch/arm64/include/asm/kvm_arm.h |  4 +++-
 arch/arm64/include/asm/sysreg.h  |  3 +++
 arch/arm64/kvm/hyp/s2-setup.c    |  6 +++--
 4 files changed, 43 insertions(+), 22 deletions(-)

[PULL 1/2] arm64: kvm: 4.6-rc1: Fix VTCR_EL2 VS setting

[Christoffer Dall]

From: Suzuki K Poulose <suzuki.poulose@arm.com>

When we detect support for 16bit VMID in ID_AA64MMFR1, we set the
VTCR_EL2_VS field to 1 to make use of 16bit vmids. But, with
commit 3a3604bc5eb4 ("arm64: KVM: Switch to C-based stage2 init")
this is broken and we corrupt VTCR_EL2:T0SZ instead of updating the VS
field. VTCR_EL2_VS was actually defined to the field shift (19) and
not the real value for VS. This patch fixes the issue.

Fixes: commit 3a3604bc5eb4 ("arm64: KVM: Switch to C-based stage2 init")
Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm64/include/asm/kvm_arm.h | 4 +++-
 arch/arm64/include/asm/sysreg.h  | 3 +++
 arch/arm64/kvm/hyp/s2-setup.c    | 6 ++++--
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 0e391db..4150fd8 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -124,7 +124,9 @@
 #define VTCR_EL2_SL0_LVL1	(1 << 6)
 #define VTCR_EL2_T0SZ_MASK	0x3f
 #define VTCR_EL2_T0SZ_40B	24
-#define VTCR_EL2_VS		19
+#define VTCR_EL2_VS_SHIFT	19
+#define VTCR_EL2_VS_8BIT	(0 << VTCR_EL2_VS_SHIFT)
+#define VTCR_EL2_VS_16BIT	(1 << VTCR_EL2_VS_SHIFT)
 
 /*
  * We configure the Stage-2 page tables to always restrict the IPA space to be
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h
index 1a78d6e..1287416 100644
--- a/arch/arm64/include/asm/sysreg.h
+++ b/arch/arm64/include/asm/sysreg.h
@@ -141,6 +141,9 @@
 #define ID_AA64MMFR1_VMIDBITS_SHIFT	4
 #define ID_AA64MMFR1_HADBS_SHIFT	0
 
+#define ID_AA64MMFR1_VMIDBITS_8		0
+#define ID_AA64MMFR1_VMIDBITS_16	2
+
 /* id_aa64mmfr2 */
 #define ID_AA64MMFR2_UAO_SHIFT		4
 
diff --git a/arch/arm64/kvm/hyp/s2-setup.c b/arch/arm64/kvm/hyp/s2-setup.c
index bfc54fd..5a9f3bf 100644
--- a/arch/arm64/kvm/hyp/s2-setup.c
+++ b/arch/arm64/kvm/hyp/s2-setup.c
@@ -36,8 +36,10 @@ void __hyp_text __init_stage2_translation(void)
 	 * Read the VMIDBits bits from ID_AA64MMFR1_EL1 and set the VS
 	 * bit in VTCR_EL2.
 	 */
-	tmp = (read_sysreg(id_aa64mmfr1_el1) >> 4) & 0xf;
-	val |= (tmp == 2) ? VTCR_EL2_VS : 0;
+	tmp = (read_sysreg(id_aa64mmfr1_el1) >> ID_AA64MMFR1_VMIDBITS_SHIFT) & 0xf;
+	val |= (tmp == ID_AA64MMFR1_VMIDBITS_16) ?
+			VTCR_EL2_VS_16BIT :
+			VTCR_EL2_VS_8BIT;
 
 	write_sysreg(val, vtcr_el2);
 }
-- 
2.1.2.330.g565301e.dirty

[PULL 2/2] arm64: KVM: Register CPU notifiers when the kernel runs at HYP

[Christoffer Dall]

From: James Morse <james.morse@arm.com>

When the kernel is running at EL2, it doesn't need init_hyp_mode() to
configure page tables for HYP. This function also registers the CPU
hotplug and lower power notifiers that cause HYP to be re-initialised
after the CPU has been reset.

To avoid losing the register state that controls stage2 translation, move
the registering of these notifiers into init_subsystems(), and add a
is_kernel_in_hyp_mode() path to each callback.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Fixes: 1e947bad0b6 ("arm64: KVM: Skip HYP setup when already running in HYP")
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
---
 arch/arm/kvm/arm.c | 52 +++++++++++++++++++++++++++++++++-------------------
 1 file changed, 33 insertions(+), 19 deletions(-)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 6accd66..b538431 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -1061,15 +1061,27 @@ static void cpu_init_hyp_mode(void *dummy)
 	kvm_arm_init_debug();
 }
 
+static void cpu_hyp_reinit(void)
+{
+	if (is_kernel_in_hyp_mode()) {
+		/*
+		 * cpu_init_stage2() is safe to call even if the PM
+		 * event was cancelled before the CPU was reset.
+		 */
+		cpu_init_stage2(NULL);
+	} else {
+		if (__hyp_get_vectors() == hyp_default_vectors)
+			cpu_init_hyp_mode(NULL);
+	}
+}
+
 static int hyp_init_cpu_notify(struct notifier_block *self,
 			       unsigned long action, void *cpu)
 {
 	switch (action) {
 	case CPU_STARTING:
 	case CPU_STARTING_FROZEN:
-		if (__hyp_get_vectors() == hyp_default_vectors)
-			cpu_init_hyp_mode(NULL);
-		break;
+		cpu_hyp_reinit();
 	}
 
 	return NOTIFY_OK;
@@ -1084,9 +1096,8 @@ static int hyp_init_cpu_pm_notifier(struct notifier_block *self,
 				    unsigned long cmd,
 				    void *v)
 {
-	if (cmd == CPU_PM_EXIT &&
-	    __hyp_get_vectors() == hyp_default_vectors) {
-		cpu_init_hyp_mode(NULL);
+	if (cmd == CPU_PM_EXIT) {
+		cpu_hyp_reinit();
 		return NOTIFY_OK;
 	}
 
@@ -1128,6 +1139,22 @@ static int init_subsystems(void)
 	int err;
 
 	/*
+	 * Register CPU Hotplug notifier
+	 */
+	cpu_notifier_register_begin();
+	err = __register_cpu_notifier(&hyp_init_cpu_nb);
+	cpu_notifier_register_done();
+	if (err) {
+		kvm_err("Cannot register KVM init CPU notifier (%d)\n", err);
+		return err;
+	}
+
+	/*
+	 * Register CPU lower-power notifier
+	 */
+	hyp_cpu_pm_init();
+
+	/*
 	 * Init HYP view of VGIC
 	 */
 	err = kvm_vgic_hyp_init();
@@ -1270,19 +1297,6 @@ static int init_hyp_mode(void)
 	free_boot_hyp_pgd();
 #endif
 
-	cpu_notifier_register_begin();
-
-	err = __register_cpu_notifier(&hyp_init_cpu_nb);
-
-	cpu_notifier_register_done();
-
-	if (err) {
-		kvm_err("Cannot register HYP init CPU notifier (%d)\n", err);
-		goto out_err;
-	}
-
-	hyp_cpu_pm_init();
-
 	/* set size of VMID supported by CPU */
 	kvm_vmid_bits = kvm_get_vmid_bits();
 	kvm_info("%d-bit VMID\n", kvm_vmid_bits);
-- 
2.1.2.330.g565301e.dirty

[PULL 0/2] KVM/ARM Fixes for v4.6-rc2

[Paolo Bonzini]

On 01/04/2016 11:07, Christoffer Dall wrote:
> Hi Paolo,
> 
> The following changes since commit f55532a0c0b8bb6148f4e07853b876ef73bc69ca:
> 
>   Linux 4.6-rc1 (2016-03-26 16:03:24 -0700)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git tags/kvm-arm-for-4.6-rc2
> 
> for you to fetch changes up to 5f5560b1c5f3a80e91c6babb2da34a51943bbdec:
> 
>   arm64: KVM: Register CPU notifiers when the kernel runs at HYP (2016-03-31 10:27:28 +0200)
> 
> The pull contains two small patches that fix a bug that corrupts stage-2
> translationson 16-bit VMID equipped systems and fixCPU PM and Hotplug after
> the EL2 init code has been moved to C.
> 
> Thanks,
> -Christoffer
> 
> ---
> 
> James Morse (1):
>       arm64: KVM: Register CPU notifiers when the kernel runs at HYP
> 
> Suzuki K Poulose (1):
>       arm64: kvm: 4.6-rc1: Fix VTCR_EL2 VS setting
> 
>  arch/arm/kvm/arm.c               | 52 +++++++++++++++++++++++++---------------
>  arch/arm64/include/asm/kvm_arm.h |  4 +++-
>  arch/arm64/include/asm/sysreg.h  |  3 +++
>  arch/arm64/kvm/hyp/s2-setup.c    |  6 +++--
>  4 files changed, 43 insertions(+), 22 deletions(-)

Pulled to kvm/queue, thanks.

Paolo