Commit b22498c4 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

Merge branch kvm-arm64/timer-vm-offsets into kvmarm-master/next 



* kvm-arm64/timer-vm-offsets: (21 commits)
  : .
  : This series aims at satisfying multiple goals:
  :
  : - allow a VMM to atomically restore a timer offset for a whole VM
  :   instead of updating the offset each time a vcpu get its counter
  :   written
  :
  : - allow a VMM to save/restore the physical timer context, something
  :   that we cannot do at the moment due to the lack of offsetting
  :
  : - provide a framework that is suitable for NV support, where we get
  :   both global and per timer, per vcpu offsetting, and manage
  :   interrupts in a less braindead way.
  :
  : Conflict resolution involves using the new per-vcpu config lock instead
  : of the home-grown timer lock.
  : .
  KVM: arm64: Handle 32bit CNTPCTSS traps
  KVM: arm64: selftests: Augment existing timer test to handle variable offset
  KVM: arm64: selftests: Deal with spurious timer interrupts
  KVM: arm64: selftests: Add physical timer registers to the sysreg list
  KVM: arm64: nv: timers: Support hyp timer emulation
  KVM: arm64: nv: timers: Add a per-timer, per-vcpu offset
  KVM: arm64: Document KVM_ARM_SET_CNT_OFFSETS and co
  KVM: arm64: timers: Abstract the number of valid timers per vcpu
  KVM: arm64: timers: Fast-track CNTPCT_EL0 trap handling
  KVM: arm64: Elide kern_hyp_va() in VHE-specific parts of the hypervisor
  KVM: arm64: timers: Move the timer IRQs into arch_timer_vm_data
  KVM: arm64: timers: Abstract per-timer IRQ access
  KVM: arm64: timers: Rationalise per-vcpu timer init
  KVM: arm64: timers: Allow save/restoring of the physical timer
  KVM: arm64: timers: Allow userspace to set the global counter offset
  KVM: arm64: Expose {un,}lock_all_vcpus() to the rest of KVM
  KVM: arm64: timers: Allow physical offset without CNTPOFF_EL2
  KVM: arm64: timers: Use CNTPOFF_EL2 to offset the physical timer
  arm64: Add HAS_ECV_CNTPOFF capability
  arm64: Add CNTPOFF_EL2 register definition
  ...

Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parents ef5f97e9 a6610435

Documentation/virt/kvm/api.rst

+38 −0
Original line number Diff line number Diff line
@@ -6029,6 +6029,44 @@ delivery must be provided via the "reg_aen" struct. 
The "pad" and "reserved" fields may be used for future extensions and should be

set to 0s by userspace.



4.138 KVM_ARM_SET_COUNTER_OFFSET

--------------------------------



:Capability: KVM_CAP_COUNTER_OFFSET

:Architectures: arm64

:Type: vm ioctl

:Parameters: struct kvm_arm_counter_offset (in)

:Returns: 0 on success, < 0 on error



This capability indicates that userspace is able to apply a single VM-wide

offset to both the virtual and physical counters as viewed by the guest

using the KVM_ARM_SET_CNT_OFFSET ioctl and the following data structure:



::



	struct kvm_arm_counter_offset {

		__u64 counter_offset;

		__u64 reserved;

	};



The offset describes a number of counter cycles that are subtracted from

both virtual and physical counter views (similar to the effects of the

CNTVOFF_EL2 and CNTPOFF_EL2 system registers, but only global). The offset

always applies to all vcpus (already created or created after this ioctl)

for this VM.



It is userspace's responsibility to compute the offset based, for example,

on previous values of the guest counters.



Any value other than 0 for the "reserved" field may result in an error

(-EINVAL) being returned. This ioctl can also return -EBUSY if any vcpu

ioctl is issued concurrently.



Note that using this ioctl results in KVM ignoring subsequent userspace

writes to the CNTVCT_EL0 and CNTPCT_EL0 registers using the SET_ONE_REG

interface. No error will be returned, but the resulting offset will not be

applied.



5. The kvm_run structure

========================

arch/arm64/include/asm/kvm_host.h

+13 −0
Original line number Diff line number Diff line
@@ -224,6 +224,10 @@ struct kvm_arch { 
#define KVM_ARCH_FLAG_EL1_32BIT				4

	/* PSCI SYSTEM_SUSPEND enabled for the guest */

#define KVM_ARCH_FLAG_SYSTEM_SUSPEND_ENABLED		5

	/* VM counter offset */

#define KVM_ARCH_FLAG_VM_COUNTER_OFFSET			6

	/* Timer PPIs made immutable */

#define KVM_ARCH_FLAG_TIMER_PPIS_IMMUTABLE		7



	unsigned long flags;
@@ -368,6 +372,10 @@ enum vcpu_sysreg { 
	TPIDR_EL2,	/* EL2 Software Thread ID Register */

	CNTHCTL_EL2,	/* Counter-timer Hypervisor Control register */

	SP_EL2,		/* EL2 Stack Pointer */

	CNTHP_CTL_EL2,

	CNTHP_CVAL_EL2,

	CNTHV_CTL_EL2,

	CNTHV_CVAL_EL2,



	NR_SYS_REGS	/* Nothing after this line! */

};
@@ -926,6 +934,9 @@ void kvm_reset_sys_regs(struct kvm_vcpu *vcpu); 


int __init kvm_sys_reg_table_init(void);



bool lock_all_vcpus(struct kvm *kvm);

void unlock_all_vcpus(struct kvm *kvm);



/* MMIO helpers */

void kvm_mmio_write_buf(void *buf, unsigned int len, unsigned long data);

unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len);
@@ -1011,6 +1022,8 @@ int kvm_arm_vcpu_arch_has_attr(struct kvm_vcpu *vcpu, 


long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm,

				struct kvm_arm_copy_mte_tags *copy_tags);

int kvm_vm_ioctl_set_counter_offset(struct kvm *kvm,

				    struct kvm_arm_counter_offset *offset);



/* Guest/host FPSIMD coordination helpers */

int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu);

arch/arm64/include/asm/kvm_mmu.h

+4 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ 
 * specific registers encoded in the instructions).

 */

.macro kern_hyp_va	reg

#ifndef __KVM_VHE_HYPERVISOR__

alternative_cb ARM64_ALWAYS_SYSTEM, kvm_update_va_mask

	and     \reg, \reg, #1		/* mask with va_mask */

	ror	\reg, \reg, #1		/* rotate to the first tag bit */
@@ -70,6 +71,7 @@ alternative_cb ARM64_ALWAYS_SYSTEM, kvm_update_va_mask 
	add	\reg, \reg, #0, lsl 12	/* insert the top 12 bits of the tag */

	ror	\reg, \reg, #63		/* rotate back */

alternative_cb_end

#endif

.endm



/*
@@ -127,6 +129,7 @@ void kvm_apply_hyp_relocations(void); 


static __always_inline unsigned long __kern_hyp_va(unsigned long v)

{

#ifndef __KVM_VHE_HYPERVISOR__

	asm volatile(ALTERNATIVE_CB("and %0, %0, #1\n"

				    "ror %0, %0, #1\n"

				    "add %0, %0, #0\n"
@@ -135,6 +138,7 @@ static __always_inline unsigned long __kern_hyp_va(unsigned long v) 
				    ARM64_ALWAYS_SYSTEM,

				    kvm_update_va_mask)

		     : "+r" (v));

#endif

	return v;

}

arch/arm64/include/asm/sysreg.h

+3 −0
Original line number Diff line number Diff line
@@ -388,6 +388,7 @@ 


#define SYS_CNTFRQ_EL0			sys_reg(3, 3, 14, 0, 0)



#define SYS_CNTPCT_EL0			sys_reg(3, 3, 14, 0, 1)

#define SYS_CNTPCTSS_EL0		sys_reg(3, 3, 14, 0, 5)

#define SYS_CNTVCTSS_EL0		sys_reg(3, 3, 14, 0, 6)
@@ -400,7 +401,9 @@ 


#define SYS_AARCH32_CNTP_TVAL		sys_reg(0, 0, 14, 2, 0)

#define SYS_AARCH32_CNTP_CTL		sys_reg(0, 0, 14, 2, 1)

#define SYS_AARCH32_CNTPCT		sys_reg(0, 0, 0, 14, 0)

#define SYS_AARCH32_CNTP_CVAL		sys_reg(0, 2, 0, 14, 0)

#define SYS_AARCH32_CNTPCTSS		sys_reg(0, 8, 0, 14, 0)



#define __PMEV_op2(n)			((n) & 0x7)

#define __CNTR_CRm(n)			(0x8 | (((n) >> 3) & 0x3))

arch/arm64/include/uapi/asm/kvm.h

+11 −0
Original line number Diff line number Diff line
@@ -198,6 +198,15 @@ struct kvm_arm_copy_mte_tags { 
	__u64 reserved[2];

};



/*

 * Counter/Timer offset structure. Describe the virtual/physical offset.

 * To be used with KVM_ARM_SET_COUNTER_OFFSET.

 */

struct kvm_arm_counter_offset {

	__u64 counter_offset;

	__u64 reserved;

};



#define KVM_ARM_TAGS_TO_GUEST		0

#define KVM_ARM_TAGS_FROM_GUEST		1
@@ -411,6 +420,8 @@ enum { 
#define KVM_ARM_VCPU_TIMER_CTRL		1

#define   KVM_ARM_VCPU_TIMER_IRQ_VTIMER		0

#define   KVM_ARM_VCPU_TIMER_IRQ_PTIMER		1

#define   KVM_ARM_VCPU_TIMER_IRQ_HVTIMER	2

#define   KVM_ARM_VCPU_TIMER_IRQ_HPTIMER	3

#define KVM_ARM_VCPU_PVTIME_CTRL	2

#define   KVM_ARM_VCPU_PVTIME_IPA	0