KVM/ARM updates for 4.10-rc4

- Fix for timer setup on VHE machines
 - Drop spurious warning when the timer races against
   the vcpu running again
 - Prevent a vgic deadlock when the initialization fails
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Merge tag 'kvm-arm-for-4.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm

KVM/ARM updates for 4.10-rc4

- Fix for timer setup on VHE machines
- Drop spurious warning when the timer races against
  the vcpu running again
- Prevent a vgic deadlock when the initialization fails
This commit is contained in:
Radim Krčmář 2017-01-17 15:04:59 +01:00
commit 1b1973ef9a
9 changed files with 75 additions and 24 deletions

View File

@ -80,6 +80,11 @@ static inline bool is_kernel_in_hyp_mode(void)
return false;
}
static inline bool has_vhe(void)
{
return false;
}
/* The section containing the hypervisor idmap text */
extern char __hyp_idmap_text_start[];
extern char __hyp_idmap_text_end[];

View File

@ -1099,6 +1099,9 @@ static void cpu_init_hyp_mode(void *dummy)
__cpu_init_hyp_mode(pgd_ptr, hyp_stack_ptr, vector_ptr);
__cpu_init_stage2();
if (is_kernel_in_hyp_mode())
kvm_timer_init_vhe();
kvm_arm_init_debug();
}

View File

@ -47,6 +47,7 @@
#include <asm/ptrace.h>
#include <asm/sections.h>
#include <asm/sysreg.h>
#include <asm/cpufeature.h>
/*
* __boot_cpu_mode records what mode CPUs were booted in.
@ -80,6 +81,14 @@ static inline bool is_kernel_in_hyp_mode(void)
return read_sysreg(CurrentEL) == CurrentEL_EL2;
}
static inline bool has_vhe(void)
{
if (cpus_have_const_cap(ARM64_HAS_VIRT_HOST_EXTN))
return true;
return false;
}
#ifdef CONFIG_ARM64_VHE
extern void verify_cpu_run_el(void);
#else

View File

@ -76,4 +76,5 @@ void kvm_timer_unschedule(struct kvm_vcpu *vcpu);
void kvm_timer_vcpu_put(struct kvm_vcpu *vcpu);
void kvm_timer_init_vhe(void);
#endif

View File

@ -24,6 +24,7 @@
#include <clocksource/arm_arch_timer.h>
#include <asm/arch_timer.h>
#include <asm/kvm_hyp.h>
#include <kvm/arm_vgic.h>
#include <kvm/arm_arch_timer.h>
@ -89,9 +90,6 @@ static void kvm_timer_inject_irq_work(struct work_struct *work)
struct kvm_vcpu *vcpu;
vcpu = container_of(work, struct kvm_vcpu, arch.timer_cpu.expired);
vcpu->arch.timer_cpu.armed = false;
WARN_ON(!kvm_timer_should_fire(vcpu));
/*
* If the vcpu is blocked we want to wake it up so that it will see
@ -512,3 +510,25 @@ void kvm_timer_init(struct kvm *kvm)
{
kvm->arch.timer.cntvoff = kvm_phys_timer_read();
}
/*
* On VHE system, we only need to configure trap on physical timer and counter
* accesses in EL0 and EL1 once, not for every world switch.
* The host kernel runs at EL2 with HCR_EL2.TGE == 1,
* and this makes those bits have no effect for the host kernel execution.
*/
void kvm_timer_init_vhe(void)
{
/* When HCR_EL2.E2H ==1, EL1PCEN and EL1PCTEN are shifted by 10 */
u32 cnthctl_shift = 10;
u64 val;
/*
* Disallow physical timer access for the guest.
* Physical counter access is allowed.
*/
val = read_sysreg(cnthctl_el2);
val &= ~(CNTHCTL_EL1PCEN << cnthctl_shift);
val |= (CNTHCTL_EL1PCTEN << cnthctl_shift);
write_sysreg(val, cnthctl_el2);
}

View File

@ -35,10 +35,16 @@ void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu)
/* Disable the virtual timer */
write_sysreg_el0(0, cntv_ctl);
/* Allow physical timer/counter access for the host */
val = read_sysreg(cnthctl_el2);
val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
write_sysreg(val, cnthctl_el2);
/*
* We don't need to do this for VHE since the host kernel runs in EL2
* with HCR_EL2.TGE ==1, which makes those bits have no impact.
*/
if (!has_vhe()) {
/* Allow physical timer/counter access for the host */
val = read_sysreg(cnthctl_el2);
val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
write_sysreg(val, cnthctl_el2);
}
/* Clear cntvoff for the host */
write_sysreg(0, cntvoff_el2);
@ -50,14 +56,17 @@ void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu)
struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
u64 val;
/*
* Disallow physical timer access for the guest
* Physical counter access is allowed
*/
val = read_sysreg(cnthctl_el2);
val &= ~CNTHCTL_EL1PCEN;
val |= CNTHCTL_EL1PCTEN;
write_sysreg(val, cnthctl_el2);
/* Those bits are already configured at boot on VHE-system */
if (!has_vhe()) {
/*
* Disallow physical timer access for the guest
* Physical counter access is allowed
*/
val = read_sysreg(cnthctl_el2);
val &= ~CNTHCTL_EL1PCEN;
val |= CNTHCTL_EL1PCTEN;
write_sysreg(val, cnthctl_el2);
}
if (timer->enabled) {
write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2);

View File

@ -268,15 +268,11 @@ static void kvm_vgic_dist_destroy(struct kvm *kvm)
{
struct vgic_dist *dist = &kvm->arch.vgic;
mutex_lock(&kvm->lock);
dist->ready = false;
dist->initialized = false;
kfree(dist->spis);
dist->nr_spis = 0;
mutex_unlock(&kvm->lock);
}
void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
@ -286,7 +282,8 @@ void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu)
INIT_LIST_HEAD(&vgic_cpu->ap_list_head);
}
void kvm_vgic_destroy(struct kvm *kvm)
/* To be called with kvm->lock held */
static void __kvm_vgic_destroy(struct kvm *kvm)
{
struct kvm_vcpu *vcpu;
int i;
@ -297,6 +294,13 @@ void kvm_vgic_destroy(struct kvm *kvm)
kvm_vgic_vcpu_destroy(vcpu);
}
void kvm_vgic_destroy(struct kvm *kvm)
{
mutex_lock(&kvm->lock);
__kvm_vgic_destroy(kvm);
mutex_unlock(&kvm->lock);
}
/**
* vgic_lazy_init: Lazy init is only allowed if the GIC exposed to the guest
* is a GICv2. A GICv3 must be explicitly initialized by the guest using the
@ -348,6 +352,10 @@ int kvm_vgic_map_resources(struct kvm *kvm)
ret = vgic_v2_map_resources(kvm);
else
ret = vgic_v3_map_resources(kvm);
if (ret)
__kvm_vgic_destroy(kvm);
out:
mutex_unlock(&kvm->lock);
return ret;

View File

@ -293,8 +293,6 @@ int vgic_v2_map_resources(struct kvm *kvm)
dist->ready = true;
out:
if (ret)
kvm_vgic_destroy(kvm);
return ret;
}

View File

@ -302,8 +302,6 @@ int vgic_v3_map_resources(struct kvm *kvm)
dist->ready = true;
out:
if (ret)
kvm_vgic_destroy(kvm);
return ret;
}