Contributors: 27
Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
Marc Zyngier |
1151 |
63.10% |
45 |
39.82% |
Oliver Upton |
166 |
9.10% |
6 |
5.31% |
David Brazdil |
137 |
7.51% |
2 |
1.77% |
Christoffer Dall |
89 |
4.88% |
12 |
10.62% |
James Morse |
65 |
3.56% |
7 |
6.19% |
Fuad Tabba |
64 |
3.51% |
7 |
6.19% |
Reiji Watanabe |
28 |
1.54% |
1 |
0.88% |
Andrew Scull |
23 |
1.26% |
5 |
4.42% |
Dave P Martin |
21 |
1.15% |
6 |
5.31% |
Jintack Lim |
15 |
0.82% |
1 |
0.88% |
Mark Rutland |
13 |
0.71% |
1 |
0.88% |
Alex Bennée |
8 |
0.44% |
2 |
1.77% |
Andre Przywara |
7 |
0.38% |
3 |
2.65% |
Julien Thierry |
6 |
0.33% |
2 |
1.77% |
Kristina Martšenko |
6 |
0.33% |
1 |
0.88% |
Akihiko Odaki |
6 |
0.33% |
1 |
0.88% |
Vladimir Murzin |
3 |
0.16% |
1 |
0.88% |
Catalin Marinas |
3 |
0.16% |
1 |
0.88% |
Rob Herring |
2 |
0.11% |
1 |
0.88% |
Shannon Zhao |
2 |
0.11% |
1 |
0.88% |
Thomas Gleixner |
2 |
0.11% |
1 |
0.88% |
Gavin Shan |
2 |
0.11% |
1 |
0.88% |
Andrew Murray |
1 |
0.05% |
1 |
0.88% |
Quentin Perret |
1 |
0.05% |
1 |
0.88% |
Ionela Voinescu |
1 |
0.05% |
1 |
0.88% |
Pierre-Clément Tosi |
1 |
0.05% |
1 |
0.88% |
Steven Price |
1 |
0.05% |
1 |
0.88% |
Total |
1824 |
|
113 |
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#include <hyp/switch.h>
#include <linux/arm-smccc.h>
#include <linux/kvm_host.h>
#include <linux/types.h>
#include <linux/jump_label.h>
#include <linux/percpu.h>
#include <uapi/linux/psci.h>
#include <kvm/arm_psci.h>
#include <asm/barrier.h>
#include <asm/cpufeature.h>
#include <asm/kprobes.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_hyp.h>
#include <asm/kvm_mmu.h>
#include <asm/fpsimd.h>
#include <asm/debug-monitors.h>
#include <asm/processor.h>
#include <asm/thread_info.h>
#include <asm/vectors.h>
/* VHE specific context */
DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data);
DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt);
DEFINE_PER_CPU(unsigned long, kvm_hyp_vector);
/*
* HCR_EL2 bits that the NV guest can freely change (no RES0/RES1
* semantics, irrespective of the configuration), but that cannot be
* applied to the actual HW as things would otherwise break badly.
*
* - TGE: we want the guest to use EL1, which is incompatible with
* this bit being set
*
* - API/APK: they are already accounted for by vcpu_load(), and can
* only take effect across a load/put cycle (such as ERET)
*/
#define NV_HCR_GUEST_EXCLUDE (HCR_TGE | HCR_API | HCR_APK)
static u64 __compute_hcr(struct kvm_vcpu *vcpu)
{
u64 hcr = vcpu->arch.hcr_el2;
if (!vcpu_has_nv(vcpu))
return hcr;
if (is_hyp_ctxt(vcpu)) {
hcr |= HCR_NV | HCR_NV2 | HCR_AT | HCR_TTLB;
if (!vcpu_el2_e2h_is_set(vcpu))
hcr |= HCR_NV1;
write_sysreg_s(vcpu->arch.ctxt.vncr_array, SYS_VNCR_EL2);
}
return hcr | (__vcpu_sys_reg(vcpu, HCR_EL2) & ~NV_HCR_GUEST_EXCLUDE);
}
static void __activate_cptr_traps(struct kvm_vcpu *vcpu)
{
u64 cptr;
/*
* With VHE (HCR.E2H == 1), accesses to CPACR_EL1 are routed to
* CPTR_EL2. In general, CPACR_EL1 has the same layout as CPTR_EL2,
* except for some missing controls, such as TAM.
* In this case, CPTR_EL2.TAM has the same position with or without
* VHE (HCR.E2H == 1) which allows us to use here the CPTR_EL2.TAM
* shift value for trapping the AMU accesses.
*/
u64 val = CPACR_ELx_TTA | CPTR_EL2_TAM;
if (guest_owns_fp_regs()) {
val |= CPACR_ELx_FPEN;
if (vcpu_has_sve(vcpu))
val |= CPACR_ELx_ZEN;
} else {
__activate_traps_fpsimd32(vcpu);
}
if (!vcpu_has_nv(vcpu))
goto write;
/*
* The architecture is a bit crap (what a surprise): an EL2 guest
* writing to CPTR_EL2 via CPACR_EL1 can't set any of TCPAC or TTA,
* as they are RES0 in the guest's view. To work around it, trap the
* sucker using the very same bit it can't set...
*/
if (vcpu_el2_e2h_is_set(vcpu) && is_hyp_ctxt(vcpu))
val |= CPTR_EL2_TCPAC;
/*
* Layer the guest hypervisor's trap configuration on top of our own if
* we're in a nested context.
*/
if (is_hyp_ctxt(vcpu))
goto write;
cptr = vcpu_sanitised_cptr_el2(vcpu);
/*
* Pay attention, there's some interesting detail here.
*
* The CPTR_EL2.xEN fields are 2 bits wide, although there are only two
* meaningful trap states when HCR_EL2.TGE = 0 (running a nested guest):
*
* - CPTR_EL2.xEN = x0, traps are enabled
* - CPTR_EL2.xEN = x1, traps are disabled
*
* In other words, bit[0] determines if guest accesses trap or not. In
* the interest of simplicity, clear the entire field if the guest
* hypervisor has traps enabled to dispel any illusion of something more
* complicated taking place.
*/
if (!(SYS_FIELD_GET(CPACR_ELx, FPEN, cptr) & BIT(0)))
val &= ~CPACR_ELx_FPEN;
if (!(SYS_FIELD_GET(CPACR_ELx, ZEN, cptr) & BIT(0)))
val &= ~CPACR_ELx_ZEN;
if (kvm_has_feat(vcpu->kvm, ID_AA64MMFR3_EL1, S2POE, IMP))
val |= cptr & CPACR_ELx_E0POE;
val |= cptr & CPTR_EL2_TCPAC;
write:
write_sysreg(val, cpacr_el1);
}
static void __activate_traps(struct kvm_vcpu *vcpu)
{
u64 val;
___activate_traps(vcpu, __compute_hcr(vcpu));
if (has_cntpoff()) {
struct timer_map map;
get_timer_map(vcpu, &map);
/*
* We're entrering the guest. Reload the correct
* values from memory now that TGE is clear.
*/
if (map.direct_ptimer == vcpu_ptimer(vcpu))
val = __vcpu_sys_reg(vcpu, CNTP_CVAL_EL0);
if (map.direct_ptimer == vcpu_hptimer(vcpu))
val = __vcpu_sys_reg(vcpu, CNTHP_CVAL_EL2);
if (map.direct_ptimer) {
write_sysreg_el0(val, SYS_CNTP_CVAL);
isb();
}
}
__activate_cptr_traps(vcpu);
write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el1);
}
NOKPROBE_SYMBOL(__activate_traps);
static void __deactivate_traps(struct kvm_vcpu *vcpu)
{
const char *host_vectors = vectors;
___deactivate_traps(vcpu);
write_sysreg(HCR_HOST_VHE_FLAGS, hcr_el2);
if (has_cntpoff()) {
struct timer_map map;
u64 val, offset;
get_timer_map(vcpu, &map);
/*
* We're exiting the guest. Save the latest CVAL value
* to memory and apply the offset now that TGE is set.
*/
val = read_sysreg_el0(SYS_CNTP_CVAL);
if (map.direct_ptimer == vcpu_ptimer(vcpu))
__vcpu_sys_reg(vcpu, CNTP_CVAL_EL0) = val;
if (map.direct_ptimer == vcpu_hptimer(vcpu))
__vcpu_sys_reg(vcpu, CNTHP_CVAL_EL2) = val;
offset = read_sysreg_s(SYS_CNTPOFF_EL2);
if (map.direct_ptimer && offset) {
write_sysreg_el0(val + offset, SYS_CNTP_CVAL);
isb();
}
}
/*
* ARM errata 1165522 and 1530923 require the actual execution of the
* above before we can switch to the EL2/EL0 translation regime used by
* the host.
*/
asm(ALTERNATIVE("nop", "isb", ARM64_WORKAROUND_SPECULATIVE_AT));
kvm_reset_cptr_el2(vcpu);
if (!arm64_kernel_unmapped_at_el0())
host_vectors = __this_cpu_read(this_cpu_vector);
write_sysreg(host_vectors, vbar_el1);
}
NOKPROBE_SYMBOL(__deactivate_traps);
/*
* Disable IRQs in __vcpu_{load,put}_{activate,deactivate}_traps() to
* prevent a race condition between context switching of PMUSERENR_EL0
* in __{activate,deactivate}_traps_common() and IPIs that attempts to
* update PMUSERENR_EL0. See also kvm_set_pmuserenr().
*/
static void __vcpu_load_activate_traps(struct kvm_vcpu *vcpu)
{
unsigned long flags;
local_irq_save(flags);
__activate_traps_common(vcpu);
local_irq_restore(flags);
}
static void __vcpu_put_deactivate_traps(struct kvm_vcpu *vcpu)
{
unsigned long flags;
local_irq_save(flags);
__deactivate_traps_common(vcpu);
local_irq_restore(flags);
}
void kvm_vcpu_load_vhe(struct kvm_vcpu *vcpu)
{
host_data_ptr(host_ctxt)->__hyp_running_vcpu = vcpu;
__vcpu_load_switch_sysregs(vcpu);
__vcpu_load_activate_traps(vcpu);
__load_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch);
}
void kvm_vcpu_put_vhe(struct kvm_vcpu *vcpu)
{
__vcpu_put_deactivate_traps(vcpu);
__vcpu_put_switch_sysregs(vcpu);
host_data_ptr(host_ctxt)->__hyp_running_vcpu = NULL;
}
static bool kvm_hyp_handle_eret(struct kvm_vcpu *vcpu, u64 *exit_code)
{
u64 esr = kvm_vcpu_get_esr(vcpu);
u64 spsr, elr, mode;
/*
* Going through the whole put/load motions is a waste of time
* if this is a VHE guest hypervisor returning to its own
* userspace, or the hypervisor performing a local exception
* return. No need to save/restore registers, no need to
* switch S2 MMU. Just do the canonical ERET.
*
* Unless the trap has to be forwarded further down the line,
* of course...
*/
if ((__vcpu_sys_reg(vcpu, HCR_EL2) & HCR_NV) ||
(__vcpu_sys_reg(vcpu, HFGITR_EL2) & HFGITR_EL2_ERET))
return false;
spsr = read_sysreg_el1(SYS_SPSR);
mode = spsr & (PSR_MODE_MASK | PSR_MODE32_BIT);
switch (mode) {
case PSR_MODE_EL0t:
if (!(vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu)))
return false;
break;
case PSR_MODE_EL2t:
mode = PSR_MODE_EL1t;
break;
case PSR_MODE_EL2h:
mode = PSR_MODE_EL1h;
break;
default:
return false;
}
/* If ERETAx fails, take the slow path */
if (esr_iss_is_eretax(esr)) {
if (!(vcpu_has_ptrauth(vcpu) && kvm_auth_eretax(vcpu, &elr)))
return false;
} else {
elr = read_sysreg_el1(SYS_ELR);
}
spsr = (spsr & ~(PSR_MODE_MASK | PSR_MODE32_BIT)) | mode;
write_sysreg_el2(spsr, SYS_SPSR);
write_sysreg_el2(elr, SYS_ELR);
return true;
}
static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu)
{
__fpsimd_save_state(*host_data_ptr(fpsimd_state));
}
static bool kvm_hyp_handle_tlbi_el2(struct kvm_vcpu *vcpu, u64 *exit_code)
{
int ret = -EINVAL;
u32 instr;
u64 val;
/*
* Ideally, we would never trap on EL2 S1 TLB invalidations using
* the EL1 instructions when the guest's HCR_EL2.{E2H,TGE}=={1,1}.
* But "thanks" to FEAT_NV2, we don't trap writes to HCR_EL2,
* meaning that we can't track changes to the virtual TGE bit. So we
* have to leave HCR_EL2.TTLB set on the host. Oopsie...
*
* Try and handle these invalidation as quickly as possible, without
* fully exiting. Note that we don't need to consider any forwarding
* here, as having E2H+TGE set is the very definition of being
* InHost.
*
* For the lesser hypervisors out there that have failed to get on
* with the VHE program, we can also handle the nVHE style of EL2
* invalidation.
*/
if (!(is_hyp_ctxt(vcpu)))
return false;
instr = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));
val = vcpu_get_reg(vcpu, kvm_vcpu_sys_get_rt(vcpu));
if ((kvm_supported_tlbi_s1e1_op(vcpu, instr) &&
vcpu_el2_e2h_is_set(vcpu) && vcpu_el2_tge_is_set(vcpu)) ||
kvm_supported_tlbi_s1e2_op (vcpu, instr))
ret = __kvm_tlbi_s1e2(NULL, val, instr);
if (ret)
return false;
__kvm_skip_instr(vcpu);
return true;
}
static bool kvm_hyp_handle_cpacr_el1(struct kvm_vcpu *vcpu, u64 *exit_code)
{
u64 esr = kvm_vcpu_get_esr(vcpu);
int rt;
if (!is_hyp_ctxt(vcpu) || esr_sys64_to_sysreg(esr) != SYS_CPACR_EL1)
return false;
rt = kvm_vcpu_sys_get_rt(vcpu);
if ((esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ) {
vcpu_set_reg(vcpu, rt, __vcpu_sys_reg(vcpu, CPTR_EL2));
} else {
vcpu_write_sys_reg(vcpu, vcpu_get_reg(vcpu, rt), CPTR_EL2);
__activate_cptr_traps(vcpu);
}
__kvm_skip_instr(vcpu);
return true;
}
static bool kvm_hyp_handle_zcr_el2(struct kvm_vcpu *vcpu, u64 *exit_code)
{
u32 sysreg = esr_sys64_to_sysreg(kvm_vcpu_get_esr(vcpu));
if (!vcpu_has_nv(vcpu))
return false;
if (sysreg != SYS_ZCR_EL2)
return false;
if (guest_owns_fp_regs())
return false;
/*
* ZCR_EL2 traps are handled in the slow path, with the expectation
* that the guest's FP context has already been loaded onto the CPU.
*
* Load the guest's FP context and unconditionally forward to the
* slow path for handling (i.e. return false).
*/
kvm_hyp_handle_fpsimd(vcpu, exit_code);
return false;
}
static bool kvm_hyp_handle_sysreg_vhe(struct kvm_vcpu *vcpu, u64 *exit_code)
{
if (kvm_hyp_handle_tlbi_el2(vcpu, exit_code))
return true;
if (kvm_hyp_handle_cpacr_el1(vcpu, exit_code))
return true;
if (kvm_hyp_handle_zcr_el2(vcpu, exit_code))
return true;
return kvm_hyp_handle_sysreg(vcpu, exit_code);
}
static const exit_handler_fn hyp_exit_handlers[] = {
[0 ... ESR_ELx_EC_MAX] = NULL,
[ESR_ELx_EC_CP15_32] = kvm_hyp_handle_cp15_32,
[ESR_ELx_EC_SYS64] = kvm_hyp_handle_sysreg_vhe,
[ESR_ELx_EC_SVE] = kvm_hyp_handle_fpsimd,
[ESR_ELx_EC_FP_ASIMD] = kvm_hyp_handle_fpsimd,
[ESR_ELx_EC_IABT_LOW] = kvm_hyp_handle_iabt_low,
[ESR_ELx_EC_DABT_LOW] = kvm_hyp_handle_dabt_low,
[ESR_ELx_EC_WATCHPT_LOW] = kvm_hyp_handle_watchpt_low,
[ESR_ELx_EC_ERET] = kvm_hyp_handle_eret,
[ESR_ELx_EC_MOPS] = kvm_hyp_handle_mops,
};
static const exit_handler_fn *kvm_get_exit_handler_array(struct kvm_vcpu *vcpu)
{
return hyp_exit_handlers;
}
static void early_exit_filter(struct kvm_vcpu *vcpu, u64 *exit_code)
{
/*
* If we were in HYP context on entry, adjust the PSTATE view
* so that the usual helpers work correctly.
*/
if (vcpu_has_nv(vcpu) && (read_sysreg(hcr_el2) & HCR_NV)) {
u64 mode = *vcpu_cpsr(vcpu) & (PSR_MODE_MASK | PSR_MODE32_BIT);
switch (mode) {
case PSR_MODE_EL1t:
mode = PSR_MODE_EL2t;
break;
case PSR_MODE_EL1h:
mode = PSR_MODE_EL2h;
break;
}
*vcpu_cpsr(vcpu) &= ~(PSR_MODE_MASK | PSR_MODE32_BIT);
*vcpu_cpsr(vcpu) |= mode;
}
}
/* Switch to the guest for VHE systems running in EL2 */
static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *guest_ctxt;
u64 exit_code;
host_ctxt = host_data_ptr(host_ctxt);
guest_ctxt = &vcpu->arch.ctxt;
sysreg_save_host_state_vhe(host_ctxt);
/*
* Note that ARM erratum 1165522 requires us to configure both stage 1
* and stage 2 translation for the guest context before we clear
* HCR_EL2.TGE. The stage 1 and stage 2 guest context has already been
* loaded on the CPU in kvm_vcpu_load_vhe().
*/
__activate_traps(vcpu);
__kvm_adjust_pc(vcpu);
sysreg_restore_guest_state_vhe(guest_ctxt);
__debug_switch_to_guest(vcpu);
do {
/* Jump in the fire! */
exit_code = __guest_enter(vcpu);
/* And we're baaack! */
} while (fixup_guest_exit(vcpu, &exit_code));
sysreg_save_guest_state_vhe(guest_ctxt);
__deactivate_traps(vcpu);
sysreg_restore_host_state_vhe(host_ctxt);
if (guest_owns_fp_regs())
__fpsimd_save_fpexc32(vcpu);
__debug_switch_to_host(vcpu);
return exit_code;
}
NOKPROBE_SYMBOL(__kvm_vcpu_run_vhe);
int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
{
int ret;
local_daif_mask();
/*
* Having IRQs masked via PMR when entering the guest means the GIC
* will not signal the CPU of interrupts of lower priority, and the
* only way to get out will be via guest exceptions.
* Naturally, we want to avoid this.
*
* local_daif_mask() already sets GIC_PRIO_PSR_I_SET, we just need a
* dsb to ensure the redistributor is forwards EL2 IRQs to the CPU.
*/
pmr_sync();
ret = __kvm_vcpu_run_vhe(vcpu);
/*
* local_daif_restore() takes care to properly restore PSTATE.DAIF
* and the GIC PMR if the host is using IRQ priorities.
*/
local_daif_restore(DAIF_PROCCTX_NOIRQ);
/*
* When we exit from the guest we change a number of CPU configuration
* parameters, such as traps. We rely on the isb() in kvm_call_hyp*()
* to make sure these changes take effect before running the host or
* additional guests.
*/
return ret;
}
static void __noreturn __hyp_call_panic(u64 spsr, u64 elr, u64 par)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_vcpu *vcpu;
host_ctxt = host_data_ptr(host_ctxt);
vcpu = host_ctxt->__hyp_running_vcpu;
__deactivate_traps(vcpu);
sysreg_restore_host_state_vhe(host_ctxt);
panic("HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n",
spsr, elr,
read_sysreg_el2(SYS_ESR), read_sysreg_el2(SYS_FAR),
read_sysreg(hpfar_el2), par, vcpu);
}
NOKPROBE_SYMBOL(__hyp_call_panic);
void __noreturn hyp_panic(void)
{
u64 spsr = read_sysreg_el2(SYS_SPSR);
u64 elr = read_sysreg_el2(SYS_ELR);
u64 par = read_sysreg_par();
__hyp_call_panic(spsr, elr, par);
}
asmlinkage void kvm_unexpected_el2_exception(void)
{
__kvm_unexpected_el2_exception();
}