From cb678d6016510cc8c6572dd9f426fe74dd4eda84 Mon Sep 17 00:00:00 2001 From: Suzuki K Poulose Date: Wed, 30 Mar 2016 14:33:59 +0100 Subject: [PATCH 1/2] arm64: kvm: 4.6-rc1: Fix VTCR_EL2 VS setting 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 Cc: Mark Rutland Acked-by: Marc Zyngier Signed-off-by: Suzuki K Poulose Signed-off-by: Christoffer Dall --- 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 0e391dbfc420..4150fd8bae01 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 1a78d6e2a78b..12874164b0ae 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 bfc54fd82797..5a9f3bf542b0 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); } From 5f5560b1c5f3a80e91c6babb2da34a51943bbdec Mon Sep 17 00:00:00 2001 From: James Morse Date: Wed, 30 Mar 2016 18:33:04 +0100 Subject: [PATCH 2/2] arm64: KVM: Register CPU notifiers when the kernel runs at HYP 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 Acked-by: Christoffer Dall Fixes: 1e947bad0b6 ("arm64: KVM: Skip HYP setup when already running in HYP") Signed-off-by: James Morse Signed-off-by: Christoffer Dall --- 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 6accd66d26f0..b5384311dec4 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; } @@ -1127,6 +1138,22 @@ 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 */ @@ -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);