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linux/arch/arm/kvm/hyp/switch.c

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ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
/*
* 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/>.
*/
ARM: KVM: Support vgic-v3 This patch allows to build and use vgic-v3 in 32-bit mode. Unfortunately, it can not be split in several steps without extra stubs to keep patches independent and bisectable. For instance, virt/kvm/arm/vgic/vgic-v3.c uses function from vgic-v3-sr.c, handling access to GICv3 cpu interface from the guest requires vgic_v3.vgic_sre to be already defined. It is how support has been done: * handle SGI requests from the guest * report configured SRE on access to GICv3 cpu interface from the guest * required vgic-v3 macros are provided via uapi.h * static keys are used to select GIC backend * to make vgic-v3 build KVM_ARM_VGIC_V3 guard is removed along with the static inlines Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-12 15:49:24 +01:00
#include <linux/jump_label.h>
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
#include <asm/kvm_asm.h>
ARM: KVM: Move kvm/hyp/hyp.h to include/asm/kvm_hyp.h In order to be able to use the code located in virt/kvm/arm/hyp, we need to make the global hyp.h file accessible from include/asm, similar to what we did for arm64. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-28 14:31:37 +00:00
#include <asm/kvm_hyp.h>
KVM: arm/arm64: Detangle kvm_mmu.h from kvm_hyp.h kvm_hyp.h has an odd dependency on kvm_mmu.h, which makes the opposite inclusion impossible. Let's start with breaking that useless dependency. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-10-23 17:11:14 +01:00
#include <asm/kvm_mmu.h>
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
__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();
}
KVM: arm/arm64: Get rid of vcpu->arch.irq_lines We currently have a separate read-modify-write of the HCR_EL2 on entry to the guest for the sole purpose of setting the VF and VI bits, if set. Since this is most rarely the case (only when using userspace IRQ chip and interrupts are in flight), let's get rid of this operation and instead modify the bits in the vcpu->arch.hcr[_el2] directly when needed. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-08-03 12:09:05 +02:00
write_sysreg(vcpu->arch.hcr, HCR);
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
/* 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);
KVM: arm: plug potential guest hardware debug leakage Hardware debugging in guests is not intercepted currently, it means that a malicious guest can bring down the entire machine by writing to the debug registers. This patch enable trapping of all debug registers, preventing the guests to access the debug registers. This includes access to the debug mode(DBGDSCR) in the guest world all the time which could otherwise mess with the host state. Reads return 0 and writes are ignored (RAZ_WI). The result is the guest cannot detect any working hardware based debug support. As debug exceptions are still routed to the guest normal debug using software based breakpoints still works. To support debugging using hardware registers we need to implement a debug register aware world switch as well as special trapping for registers that may affect the host state. Cc: stable@vger.kernel.org Signed-off-by: Zhichao Huang <zhichao.huang@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-11 13:46:11 +01:00
val |= HDCR_TPM | HDCR_TPMCR; /* trap performance monitors */
val |= HDCR_TDRA | HDCR_TDOSA | HDCR_TDA; /* trap debug regs */
write_sysreg(val, HDCR);
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
}
static void __hyp_text __deactivate_traps(struct kvm_vcpu *vcpu)
{
u32 val;
arm: KVM: Preserve pending Virtual Abort in world switch The HCR.VA bit is used to signal an Abort to a guest, and has the peculiar feature of getting cleared when the guest has taken the abort (this is the only bit that behaves as such in this register). This means that if we signal such an abort, we must leave it in the guest context until it disappears from HCR, and at which point it must be cleared from the context. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-06 14:02:08 +01:00
/*
* 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);
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
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);
}
ARM: KVM: Support vgic-v3 This patch allows to build and use vgic-v3 in 32-bit mode. Unfortunately, it can not be split in several steps without extra stubs to keep patches independent and bisectable. For instance, virt/kvm/arm/vgic/vgic-v3.c uses function from vgic-v3-sr.c, handling access to GICv3 cpu interface from the guest requires vgic_v3.vgic_sre to be already defined. It is how support has been done: * handle SGI requests from the guest * report configured SRE on access to GICv3 cpu interface from the guest * required vgic-v3 macros are provided via uapi.h * static keys are used to select GIC backend * to make vgic-v3 build KVM_ARM_VGIC_V3 guard is removed along with the static inlines Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-12 15:49:24 +01:00
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
static void __hyp_text __vgic_save_state(struct kvm_vcpu *vcpu)
{
KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQs We can finally get completely rid of any calls to the VGICv3 save/restore functions when the AP lists are empty on VHE systems. This requires carefully factoring out trap configuration from saving and restoring state, and carefully choosing what to do on the VHE and non-VHE path. One of the challenges is that we cannot save/restore the VMCR lazily because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end up being delivered as FIQ. To solve this problem, and still provide fast performance in the fast path of exiting a VM when no interrupts are pending (which also optimized the latency for actually delivering virtual interrupts coming from physical interrupts), we orchestrate a dance of only doing the activate/deactivate traps in vgic load/put for VHE systems (which can have ICC_SRE_EL1.SRE cleared when running in the host), and doing the configuration on every round-trip on non-VHE systems. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-05 17:19:19 +02:00
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
ARM: KVM: Support vgic-v3 This patch allows to build and use vgic-v3 in 32-bit mode. Unfortunately, it can not be split in several steps without extra stubs to keep patches independent and bisectable. For instance, virt/kvm/arm/vgic/vgic-v3.c uses function from vgic-v3-sr.c, handling access to GICv3 cpu interface from the guest requires vgic_v3.vgic_sre to be already defined. It is how support has been done: * handle SGI requests from the guest * report configured SRE on access to GICv3 cpu interface from the guest * required vgic-v3 macros are provided via uapi.h * static keys are used to select GIC backend * to make vgic-v3 build KVM_ARM_VGIC_V3 guard is removed along with the static inlines Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-12 15:49:24 +01:00
__vgic_v3_save_state(vcpu);
KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQs We can finally get completely rid of any calls to the VGICv3 save/restore functions when the AP lists are empty on VHE systems. This requires carefully factoring out trap configuration from saving and restoring state, and carefully choosing what to do on the VHE and non-VHE path. One of the challenges is that we cannot save/restore the VMCR lazily because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end up being delivered as FIQ. To solve this problem, and still provide fast performance in the fast path of exiting a VM when no interrupts are pending (which also optimized the latency for actually delivering virtual interrupts coming from physical interrupts), we orchestrate a dance of only doing the activate/deactivate traps in vgic load/put for VHE systems (which can have ICC_SRE_EL1.SRE cleared when running in the host), and doing the configuration on every round-trip on non-VHE systems. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-05 17:19:19 +02:00
__vgic_v3_deactivate_traps(vcpu);
}
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
}
static void __hyp_text __vgic_restore_state(struct kvm_vcpu *vcpu)
{
KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQs We can finally get completely rid of any calls to the VGICv3 save/restore functions when the AP lists are empty on VHE systems. This requires carefully factoring out trap configuration from saving and restoring state, and carefully choosing what to do on the VHE and non-VHE path. One of the challenges is that we cannot save/restore the VMCR lazily because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end up being delivered as FIQ. To solve this problem, and still provide fast performance in the fast path of exiting a VM when no interrupts are pending (which also optimized the latency for actually delivering virtual interrupts coming from physical interrupts), we orchestrate a dance of only doing the activate/deactivate traps in vgic load/put for VHE systems (which can have ICC_SRE_EL1.SRE cleared when running in the host), and doing the configuration on every round-trip on non-VHE systems. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-05 17:19:19 +02:00
if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) {
__vgic_v3_activate_traps(vcpu);
ARM: KVM: Support vgic-v3 This patch allows to build and use vgic-v3 in 32-bit mode. Unfortunately, it can not be split in several steps without extra stubs to keep patches independent and bisectable. For instance, virt/kvm/arm/vgic/vgic-v3.c uses function from vgic-v3-sr.c, handling access to GICv3 cpu interface from the guest requires vgic_v3.vgic_sre to be already defined. It is how support has been done: * handle SGI requests from the guest * report configured SRE on access to GICv3 cpu interface from the guest * required vgic-v3 macros are provided via uapi.h * static keys are used to select GIC backend * to make vgic-v3 build KVM_ARM_VGIC_V3 guard is removed along with the static inlines Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-12 15:49:24 +01:00
__vgic_v3_restore_state(vcpu);
KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQs We can finally get completely rid of any calls to the VGICv3 save/restore functions when the AP lists are empty on VHE systems. This requires carefully factoring out trap configuration from saving and restoring state, and carefully choosing what to do on the VHE and non-VHE path. One of the challenges is that we cannot save/restore the VMCR lazily because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end up being delivered as FIQ. To solve this problem, and still provide fast performance in the fast path of exiting a VM when no interrupts are pending (which also optimized the latency for actually delivering virtual interrupts coming from physical interrupts), we orchestrate a dance of only doing the activate/deactivate traps in vgic load/put for VHE systems (which can have ICC_SRE_EL1.SRE cleared when running in the host), and doing the configuration on every round-trip on non-VHE systems. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-05 17:19:19 +02:00
}
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
}
ARM: KVM: Add populating of fault data structure On guest exit, we must take care of populating our fault data structure so that the host code can handle it. This includes resolving the IPA for permission faults, which can result in restarting the guest. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-13 19:02:51 +00:00
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;
}
KVM: arm64: Introduce VHE-specific kvm_vcpu_run So far this is mostly (see below) a copy of the legacy non-VHE switch function, but we will start reworking these functions in separate directions to work on VHE and non-VHE in the most optimal way in later patches. The only difference after this patch between the VHE and non-VHE run functions is that we omit the branch-predictor variant-2 hardening for QC Falkor CPUs, because this workaround is specific to a series of non-VHE ARMv8.0 CPUs. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-03 14:02:12 +02:00
int __hyp_text __kvm_vcpu_run_nvhe(struct kvm_vcpu *vcpu)
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
{
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);
KVM: arm/arm64: Move timer save/restore out of the hyp code As we are about to be lazy with saving and restoring the timer registers, we prepare by moving all possible timer configuration logic out of the hyp code. All virtual timer registers can be programmed from EL1 and since the arch timer is always a level triggered interrupt we can safely do this with interrupts disabled in the host kernel on the way to the guest without taking vtimer interrupts in the host kernel (yet). The downside is that the cntvoff register can only be programmed from hyp mode, so we jump into hyp mode and back to program it. This is also safe, because the host kernel doesn't use the virtual timer in the KVM code. It may add a little performance performance penalty, but only until following commits where we move this operation to vcpu load/put. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-04 16:10:28 +01:00
__timer_enable_traps(vcpu);
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
__sysreg_restore_state(guest_ctxt);
__banked_restore_state(guest_ctxt);
/* Jump in the fire! */
ARM: KVM: Add populating of fault data structure On guest exit, we must take care of populating our fault data structure so that the host code can handle it. This includes resolving the IPA for permission faults, which can result in restarting the guest. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-13 19:02:51 +00:00
again:
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
exit_code = __guest_enter(vcpu, host_ctxt);
/* And we're baaack! */
ARM: KVM: Add populating of fault data structure On guest exit, we must take care of populating our fault data structure so that the host code can handle it. This includes resolving the IPA for permission faults, which can result in restarting the guest. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-13 19:02:51 +00:00
if (exit_code == ARM_EXCEPTION_HVC && !__populate_fault_info(vcpu))
goto again;
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
fp_enabled = __vfp_enabled();
__banked_save_state(guest_ctxt);
__sysreg_save_state(guest_ctxt);
KVM: arm/arm64: Move timer save/restore out of the hyp code As we are about to be lazy with saving and restoring the timer registers, we prepare by moving all possible timer configuration logic out of the hyp code. All virtual timer registers can be programmed from EL1 and since the arch timer is always a level triggered interrupt we can safely do this with interrupts disabled in the host kernel on the way to the guest without taking vtimer interrupts in the host kernel (yet). The downside is that the cntvoff register can only be programmed from hyp mode, so we jump into hyp mode and back to program it. This is also safe, because the host kernel doesn't use the virtual timer in the KVM code. It may add a little performance performance penalty, but only until following commits where we move this operation to vcpu load/put. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-04 16:10:28 +01:00
__timer_disable_traps(vcpu);
ARM: KVM: Add the new world switch implementation The new world switch implementation is modeled after the arm64 one, calling the various save/restore functions in turn, and having as little state as possible. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-05 18:42:49 +00:00
__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;
}
ARM: KVM: Add panic handling code Instead of spinning forever, let's "properly" handle any unexpected exception ("properly" meaning "print a spat on the console and die"). This has proved useful quite a few times... Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-06 09:12:42 +00:00
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);
KVM: arm/arm64: Move timer save/restore out of the hyp code As we are about to be lazy with saving and restoring the timer registers, we prepare by moving all possible timer configuration logic out of the hyp code. All virtual timer registers can be programmed from EL1 and since the arch timer is always a level triggered interrupt we can safely do this with interrupts disabled in the host kernel on the way to the guest without taking vtimer interrupts in the host kernel (yet). The downside is that the cntvoff register can only be programmed from hyp mode, so we jump into hyp mode and back to program it. This is also safe, because the host kernel doesn't use the virtual timer in the KVM code. It may add a little performance performance penalty, but only until following commits where we move this operation to vcpu load/put. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-04 16:10:28 +01:00
__timer_disable_traps(vcpu);
ARM: KVM: Add panic handling code Instead of spinning forever, let's "properly" handle any unexpected exception ("properly" meaning "print a spat on the console and die"). This has proved useful quite a few times... Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-06 09:12:42 +00:00
__deactivate_traps(vcpu);
__deactivate_vm(vcpu);
KVM: arm: Restore banked registers and physical timer access on hyp_panic() When KVM panics, it hurridly restores the host context and parachutes into the host's panic() code. This looks like it was copied from arm64, the 32bit KVM panic code needs to restore the host's banked registers too. At some point panic() touches the physical timer/counter, this will trap back to HYP. If we're lucky, we panic again. Add a __timer_save_state() call to KVMs hyp_panic() path, this saves the guest registers and disables the traps for the host. Fixes: c36b6db5f3e4 ("ARM: KVM: Add panic handling code") Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-25 18:02:44 +01:00
__banked_restore_state(host_ctxt);
ARM: KVM: Add panic handling code Instead of spinning forever, let's "properly" handle any unexpected exception ("properly" meaning "print a spat on the console and die"). This has proved useful quite a few times... Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-01-06 09:12:42 +00:00
__sysreg_restore_state(host_ctxt);
}
/* Call panic for real */
__hyp_do_panic(__hyp_panic_string[cause], elr, val);
unreachable();
}
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