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/*
* Copyright (C) 2015 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/jump_label.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_hyp.h>
__asm__(".arch_extension virt");
/*
* Activate the traps, saving the host's fpexc register before
* overwriting it. We'll restore it on VM exit.
*/
static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu, u32 *fpexc_host)
{
u32 val;
/*
* We are about to set HCPTR.TCP10/11 to trap all floating point
* register accesses to HYP, however, the ARM ARM clearly states that
* traps are only taken to HYP if the operation would not otherwise
* trap to SVC. Therefore, always make sure that for 32-bit guests,
* we set FPEXC.EN to prevent traps to SVC, when setting the TCP bits.
*/
val = read_sysreg(VFP_FPEXC);
*fpexc_host = val;
if (!(val & FPEXC_EN)) {
write_sysreg(val | FPEXC_EN, VFP_FPEXC);
isb();
}
write_sysreg(vcpu->arch.hcr | vcpu->arch.irq_lines, HCR);
/* Trap on AArch32 cp15 c15 accesses (EL1 or EL0) */
write_sysreg(HSTR_T(15), HSTR);
write_sysreg(HCPTR_TTA | HCPTR_TCP(10) | HCPTR_TCP(11), HCPTR);
val = read_sysreg(HDCR);
val |= HDCR_TPM | HDCR_TPMCR; /* trap performance monitors */
val |= HDCR_TDRA | HDCR_TDOSA | HDCR_TDA; /* trap debug regs */
write_sysreg(val, HDCR);
}
static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu)
{
u32 val;
/*
* If we pended a virtual abort, preserve it until it gets
* cleared. See B1.9.9 (Virtual Abort exception) for details,
* but the crucial bit is the zeroing of HCR.VA in the
* pseudocode.
*/
if (vcpu->arch.hcr & HCR_VA)
vcpu->arch.hcr = read_sysreg(HCR);
write_sysreg(0, HCR);
write_sysreg(0, HSTR);
val = read_sysreg(HDCR);
write_sysreg(val & ~(HDCR_TPM | HDCR_TPMCR), HDCR);
write_sysreg(0, HCPTR);
}
static void __hyp_text __activate_vm(struct kvm_vcpu *vcpu)
{
struct kvm *kvm = kern_hyp_va(vcpu->kvm);
write_sysreg(kvm->arch.vttbr, VTTBR);
write_sysreg(vcpu->arch.midr, VPIDR);
}
static void __hyp_text __deactivate_vm(struct kvm_vcpu *vcpu)
{
write_sysreg(0, VTTBR);
write_sysreg(read_sysreg(MIDR), VPIDR);
}
static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_save_state(vcpu);
else
__vgic_v2_save_state(vcpu);
}
static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu)
{
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif))
__vgic_v3_restore_state(vcpu);
else
__vgic_v2_restore_state(vcpu);
}
static bool __hyp_text __populate_fault_info(struct kvm_vcpu *vcpu)
{
u32 hsr = read_sysreg(HSR);
u8 ec = hsr >> HSR_EC_SHIFT;
u32 hpfar, far;
vcpu->arch.fault.hsr = hsr;
if (ec == HSR_EC_IABT)
far = read_sysreg(HIFAR);
else if (ec == HSR_EC_DABT)
far = read_sysreg(HDFAR);
else
return true;
/*
* B3.13.5 Reporting exceptions taken to the Non-secure PL2 mode:
*
* Abort on the stage 2 translation for a memory access from a
* Non-secure PL1 or PL0 mode:
*
* For any Access flag fault or Translation fault, and also for any
* Permission fault on the stage 2 translation of a memory access
* made as part of a translation table walk for a stage 1 translation,
* the HPFAR holds the IPA that caused the fault. Otherwise, the HPFAR
* is UNKNOWN.
*/
if (!(hsr & HSR_DABT_S1PTW) && (hsr & HSR_FSC_TYPE) == FSC_PERM) {
u64 par, tmp;
par = read_sysreg(PAR);
write_sysreg(far, ATS1CPR);
isb();
tmp = read_sysreg(PAR);
write_sysreg(par, PAR);
if (unlikely(tmp & 1))
return false; /* Translation failed, back to guest */
hpfar = ((tmp >> 12) & ((1UL << 28) - 1)) << 4;
} else {
hpfar = read_sysreg(HPFAR);
}
vcpu->arch.fault.hxfar = far;
vcpu->arch.fault.hpfar = hpfar;
return true;
}
int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
{
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *guest_ctxt;
bool fp_enabled;
u64 exit_code;
u32 fpexc;
vcpu = kern_hyp_va(vcpu);
write_sysreg(vcpu, HTPIDR);
host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
guest_ctxt = &vcpu->arch.ctxt;
__sysreg_save_state(host_ctxt);
__banked_save_state(host_ctxt);
__activate_traps(vcpu, &fpexc);
__activate_vm(vcpu);
__vgic_restore_state(vcpu);
__timer_restore_state(vcpu);
__sysreg_restore_state(guest_ctxt);
__banked_restore_state(guest_ctxt);
/* Jump in the fire! */
again:
exit_code = __guest_enter(vcpu, host_ctxt);
/* And we're baaack! */
if (exit_code == ARM_EXCEPTION_HVC && !__populate_fault_info(vcpu))
goto again;
fp_enabled = __vfp_enabled();
__banked_save_state(guest_ctxt);
__sysreg_save_state(guest_ctxt);
__timer_save_state(vcpu);
__vgic_save_state(vcpu);
__deactivate_traps(vcpu);
__deactivate_vm(vcpu);
__banked_restore_state(host_ctxt);
__sysreg_restore_state(host_ctxt);
if (fp_enabled) {
__vfp_save_state(&guest_ctxt->vfp);
__vfp_restore_state(&host_ctxt->vfp);
}
write_sysreg(fpexc, VFP_FPEXC);
return exit_code;
}
static const char * const __hyp_panic_string[] = {
[ARM_EXCEPTION_RESET] = "\nHYP panic: RST PC:%08x CPSR:%08x",
[ARM_EXCEPTION_UNDEFINED] = "\nHYP panic: UNDEF PC:%08x CPSR:%08x",
[ARM_EXCEPTION_SOFTWARE] = "\nHYP panic: SVC PC:%08x CPSR:%08x",
[ARM_EXCEPTION_PREF_ABORT] = "\nHYP panic: PABRT PC:%08x CPSR:%08x",
[ARM_EXCEPTION_DATA_ABORT] = "\nHYP panic: DABRT PC:%08x ADDR:%08x",
[ARM_EXCEPTION_IRQ] = "\nHYP panic: IRQ PC:%08x CPSR:%08x",
[ARM_EXCEPTION_FIQ] = "\nHYP panic: FIQ PC:%08x CPSR:%08x",
[ARM_EXCEPTION_HVC] = "\nHYP panic: HVC PC:%08x CPSR:%08x",
};
void __hyp_text __noreturn __hyp_panic(int cause)
{
u32 elr = read_special(ELR_hyp);
u32 val;
if (cause == ARM_EXCEPTION_DATA_ABORT)
val = read_sysreg(HDFAR);
else
val = read_special(SPSR);
if (read_sysreg(VTTBR)) {
struct kvm_vcpu *vcpu;
struct kvm_cpu_context *host_ctxt;
vcpu = (struct kvm_vcpu *)read_sysreg(HTPIDR);
host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
__deactivate_traps(vcpu);
__deactivate_vm(vcpu);
__sysreg_restore_state(host_ctxt);
}
/* Call panic for real */
__hyp_do_panic(__hyp_panic_string[cause], elr, val);
unreachable();
}
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