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linux/arch/arm64/include/asm/kvm_asm.h

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 503 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-03 05:44:50 +00:00
/* SPDX-License-Identifier: GPL-2.0-only */
arm64: KVM: system register definitions for 64bit guests Define the saved/restored registers for 64bit guests. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-12-10 11:16:40 +00:00
/*
* Copyright (C) 2012,2013 - ARM Ltd
* Author: Marc Zyngier <marc.zyngier@arm.com>
*/
#ifndef __ARM_KVM_ASM_H__
#define __ARM_KVM_ASM_H__
arm64: KVM: remove __kvm_hyp_code_{start,end} from hyp.S We already have __hyp_text_{start,end} to express the boundaries of the HYP text section, and __kvm_hyp_code_{start,end} are getting in the way of a more modular world switch code. Just turn __kvm_hyp_code_{start,end} into #defines mapping the linker-emited symbols. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-06-26 14:16:40 +00:00
#include <asm/virt.h>
arm64: KVM: Move VCPU_WORKAROUND_2_FLAG macros to the top of the file This is to avoid potential merging conflicts between commit 55e3748e8902 ("arm64: KVM: Add ARCH_WORKAROUND_2 support for guests") and the KVM tree. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-06-02 09:42:54 +00:00
#define VCPU_WORKAROUND_2_FLAG_SHIFT 0
#define VCPU_WORKAROUND_2_FLAG (_AC(1, UL) << VCPU_WORKAROUND_2_FLAG_SHIFT)
arm64: KVM: Allow an exit code to be tagged with an SError Similarily to EL1, an asynchronous abort can be triggered whilst running at EL2. But instead of making that a new error code, we need to communicate it to the rest of KVM together with the exit reason. So let's hijack a single bit that allows the exception code to be tagged with a "pending SError" information. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-06 13:02:05 +00:00
#define ARM_EXIT_WITH_SERROR_BIT 31
#define ARM_EXCEPTION_CODE(x) ((x) & ~(1U << ARM_EXIT_WITH_SERROR_BIT))
arm/arm64: KVM: Add ARM_EXCEPTION_IS_TRAP macro 32 and 64bit use different symbols to identify the traps. 32bit has a fine grained approach (prefetch abort, data abort and HVC), while 64bit is pretty happy with just "trap". This has been fine so far, except that we now need to decode some of that in tracepoints that are common to both architectures. Introduce ARM_EXCEPTION_IS_TRAP which abstracts the trap symbols and make the tracepoint use it. Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-19 08:28:38 +00:00
#define ARM_EXCEPTION_IS_TRAP(x) (ARM_EXCEPTION_CODE((x)) == ARM_EXCEPTION_TRAP)
arm64: KVM: Allow an exit code to be tagged with an SError Similarily to EL1, an asynchronous abort can be triggered whilst running at EL2. But instead of making that a new error code, we need to communicate it to the rest of KVM together with the exit reason. So let's hijack a single bit that allows the exception code to be tagged with a "pending SError" information. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-06 13:02:05 +00:00
#define ARM_SERROR_PENDING(x) !!((x) & (1U << ARM_EXIT_WITH_SERROR_BIT))
arm64: KVM: system register definitions for 64bit guests Define the saved/restored registers for 64bit guests. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-12-10 11:16:40 +00:00
#define ARM_EXCEPTION_IRQ 0
arm64: KVM: Add exception code to report EL1 asynchronous aborts So far, we don't have a code to indicate that we've taken an asynchronous abort from EL1. Let's add one. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-06 13:02:02 +00:00
#define ARM_EXCEPTION_EL1_SERROR 1
#define ARM_EXCEPTION_TRAP 2
KVM: arm64: Safety check PSTATE when entering guest and handle IL This commit adds a paranoid check when entering the guest to make sure we don't attempt running guest code in an equally or more privilged mode than the hypervisor. We also catch other accidental programming of the SPSR_EL2 which results in an illegal exception return and report this safely back to the user. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-10-17 18:21:16 +00:00
#define ARM_EXCEPTION_IL 3
arm64: hyp/kvm: Make hyp-stub reject kvm_call_hyp() A later patch implements kvm_arch_hardware_disable(), to remove kvm from el2, and re-instate the hyp-stub. This can happen while guests are running, particularly when kvm_reboot() calls kvm_arch_hardware_disable() on each cpu. This can interrupt a guest, remove kvm, then allow the guest to be scheduled again. This causes kvm_call_hyp() to be run against the hyp-stub. Change the hyp-stub to return a new exception type when this happens, and add code to kvm's handle_exit() to tell userspace we failed to enter the guest. Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-04-27 16:47:04 +00:00
/* The hyp-stub will return this for any kvm_call_hyp() call */
arm64: hyp-stub: Define a return value for failed stub calls Define a standard return value to be returned when a hyp stub call fails, and make KVM use it for ARM_EXCEPTION_HYP_GONE (instead of using a KVM-specific value). Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-03 18:37:37 +00:00
#define ARM_EXCEPTION_HYP_GONE HVC_STUB_ERR
arm64: KVM: system register definitions for 64bit guests Define the saved/restored registers for 64bit guests. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-12-10 11:16:40 +00:00
KVM: arm/arm64: Fixup the kvm_exit tracepoint The kvm_exit tracepoint strangely always reported exits as being IRQs. This seems to be because either the __print_symbolic or the tracepoint macros use a variable named idx. Take this chance to update the fields in the tracepoint to reflect the concepts in the arm64 architecture that we pass to the tracepoint and move the exception type table to the same location and header files as the exits code. We also clear out the exception code to 0 for IRQ exits (which translates to UNKNOWN in text) to make it slighyly less confusing to parse the trace output. Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-03 20:31:24 +00:00
#define kvm_arm_exception_type \
{ARM_EXCEPTION_IRQ, "IRQ" }, \
{ARM_EXCEPTION_EL1_SERROR, "SERROR" }, \
{ARM_EXCEPTION_TRAP, "TRAP" }, \
{ARM_EXCEPTION_HYP_GONE, "HYP_GONE" }
KVM: arm64: Abstract the size of the HYP vectors pre-amble The EL2 vector hardening feature causes KVM to generate vectors for each type of CPU present in the system. The generated sequences already do some of the early guest-exit work (i.e. saving registers). To avoid duplication the generated vectors branch to the original vector just after the preamble. This size is hard coded. Adding new instructions to the HYP vector causes strange side effects, which are difficult to debug as the affected code is patched in at runtime. Add KVM_VECTOR_PREAMBLE to tell kvm_patch_vector_branch() how big the preamble is. The valid_vect macro can then validate this at build time. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-06-18 15:17:34 +00:00
/*
* Size of the HYP vectors preamble. kvm_patch_vector_branch() generates code
* that jumps over this.
*/
KVM: arm64: Consume pending SError as early as possible On systems with v8.2 we switch the 'vaxorcism' of guest SError with an alternative sequence that uses the ESB-instruction, then reads DISR_EL1. This saves the unmasking and remasking of asynchronous exceptions. We do this after we've saved the guest registers and restored the host's. Any SError that becomes pending due to this will be accounted to the guest, when it actually occurred during host-execution. Move the ESB-instruction as early as possible. Any guest SError will become pending due to this ESB-instruction and then consumed to DISR_EL1 before the host touches anything. This lets us account for host/guest SError precisely on the guest exit exception boundary. Because the ESB-instruction now lands in the preamble section of the vectors, we need to add it to the unpatched indirect vectors too, and to any sequence that may be patched in over the top. The ESB-instruction always lives in the head of the vectors, to be before any memory write. Whereas the register-store always lives in the tail. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-06-18 15:17:36 +00:00
#define KVM_VECTOR_PREAMBLE (2 * AARCH64_INSN_SIZE)
KVM: arm64: Abstract the size of the HYP vectors pre-amble The EL2 vector hardening feature causes KVM to generate vectors for each type of CPU present in the system. The generated sequences already do some of the early guest-exit work (i.e. saving registers). To avoid duplication the generated vectors branch to the original vector just after the preamble. This size is hard coded. Adding new instructions to the HYP vector causes strange side effects, which are difficult to debug as the affected code is patched in at runtime. Add KVM_VECTOR_PREAMBLE to tell kvm_patch_vector_branch() how big the preamble is. The valid_vect macro can then validate this at build time. Reviewed-by: Julien Thierry <julien.thierry@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-06-18 15:17:34 +00:00
arm64: kvm: Modernize __smccc_workaround_1_smc_start annotations In an effort to clarify and simplify the annotation of assembly functions in the kernel new macros have been introduced. These replace ENTRY and ENDPROC with separate annotations for standard C callable functions, data and code with different calling conventions. Using these for __smccc_workaround_1_smc is more involved than for most symbols as this symbol is annotated quite unusually, rather than just have the explicit symbol we define _start and _end symbols which we then use to compute the length. This does not play at all nicely with the new style macros. Instead define a constant for the size of the function and use that in both the C code and for .org based size checks in the assembly code. Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <maz@kernel.org>
2020-02-18 19:58:39 +00:00
#define __SMCCC_WORKAROUND_1_SMC_SZ 36
arm64: KVM: Use lm_alias() for kvm_ksym_ref() For historical reasons, we open-code lm_alias() in kvm_ksym_ref(). Let's use lm_alias() to avoid duplication and make things clearer. As we have to pull this from <linux/mm.h> (which is not safe for inclusion in assembly), we may as well move the kvm_ksym_ref() definition into the existing !__ASSEMBLY__ block. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Christoffer Dall <christoffer.dall@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-10 11:13:47 +00:00
#ifndef __ASSEMBLY__
#include <linux/mm.h>
arm64: KVM: add trap handlers for AArch64 debug registers Add handlers for all the AArch64 debug registers that are accessible from EL0 or EL1. The trapping code keeps track of the state of the debug registers, allowing for the switch code to implement a lazy switching strategy. Reviewed-by: Anup Patel <anup.patel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2014-04-24 09:24:46 +00:00
KVM: arm64: Handle calls to prefixed hyp functions Once hyp functions are moved to a hyp object, they will have prefixed symbols. This change declares and gets the address of the prefixed version for calls to the hyp functions. To aid migration, the hyp functions that have not yet moved have their prefixed versions aliased to their non-prefixed version. This begins with all the hyp functions being listed and will reduce to none of them once the migration is complete. Signed-off-by: Andrew Scull <ascull@google.com> [David: Extracted kvm_call_hyp nVHE branches into own helper macros, added comments around symbol aliases.] Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-6-dbrazdil@google.com
2020-06-25 13:14:10 +00:00
/*
* Translate name of a symbol defined in nVHE hyp to the name seen
* by kernel proper. All nVHE symbols are prefixed by the build system
* to avoid clashes with the VHE variants.
*/
#define kvm_nvhe_sym(sym) __kvm_nvhe_##sym
#define DECLARE_KVM_VHE_SYM(sym) extern char sym[]
#define DECLARE_KVM_NVHE_SYM(sym) extern char kvm_nvhe_sym(sym)[]
/*
* Define a pair of symbols sharing the same name but one defined in
* VHE and the other in nVHE hyp implementations.
*/
#define DECLARE_KVM_HYP_SYM(sym) \
DECLARE_KVM_VHE_SYM(sym); \
DECLARE_KVM_NVHE_SYM(sym)
KVM: arm64: Build hyp-entry.S separately for VHE/nVHE hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly shared between VHE/nVHE, therefore compile it under both VHE and nVHE build rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__. Adjust code which selects which KVM hyp vecs to install to choose the correct VHE/nVHE symbol. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-06-25 13:14:11 +00:00
#define CHOOSE_VHE_SYM(sym) sym
#define CHOOSE_NVHE_SYM(sym) kvm_nvhe_sym(sym)
KVM: arm64: Don't use has_vhe() for CHOOSE_HYP_SYM() The recently introduced CHOOSE_HYP_SYM() macro picks one symbol or another, depending on whether the kernel run as a VHE hypervisor or not. For that, it uses the has_vhe() helper, which is itself implemented as a final capability. Unfortunately, __copy_hyp_vect_bpi now indirectly uses CHOOSE_HYP_SYM to get the __bp_harden_hyp_vecs symbol, using has_vhe() in the process. At this stage, the capability isn't final and things explode: [ 0.000000] ACPI: SRAT not present [ 0.000000] percpu: Embedded 34 pages/cpu s101264 r8192 d29808 u139264 [ 0.000000] Detected PIPT I-cache on CPU0 [ 0.000000] ------------[ cut here ]------------ [ 0.000000] kernel BUG at arch/arm64/include/asm/cpufeature.h:459! [ 0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-rc4-00080-gd630681366e5 #1388 [ 0.000000] pstate: 80000085 (Nzcv daIf -PAN -UAO BTYPE=--) [ 0.000000] pc : check_branch_predictor+0x3a4/0x408 [ 0.000000] lr : check_branch_predictor+0x2a4/0x408 [ 0.000000] sp : ffff800011693e90 [ 0.000000] x29: ffff800011693e90 x28: ffff8000116a1530 [ 0.000000] x27: ffff8000112c1008 x26: ffff800010ca6ff8 [ 0.000000] x25: ffff8000112c1000 x24: ffff8000116a1320 [ 0.000000] x23: 0000000000000000 x22: ffff8000112c1000 [ 0.000000] x21: ffff800010177120 x20: ffff8000116ae108 [ 0.000000] x19: 0000000000000000 x18: ffff800011965c90 [ 0.000000] x17: 0000000000022000 x16: 0000000000000003 [ 0.000000] x15: 00000000ffffffff x14: ffff8000118c3a38 [ 0.000000] x13: 0000000000000021 x12: 0000000000000022 [ 0.000000] x11: d37a6f4de9bd37a7 x10: 000000000000001d [ 0.000000] x9 : 0000000000000000 x8 : ffff800011f8dad8 [ 0.000000] x7 : ffff800011965ad0 x6 : 0000000000000003 [ 0.000000] x5 : 0000000000000000 x4 : 0000000000000000 [ 0.000000] x3 : 0000000000000100 x2 : 0000000000000004 [ 0.000000] x1 : ffff8000116ae148 x0 : 0000000000000000 [ 0.000000] Call trace: [ 0.000000] check_branch_predictor+0x3a4/0x408 [ 0.000000] update_cpu_capabilities+0x84/0x138 [ 0.000000] init_cpu_features+0x2c0/0x2d8 [ 0.000000] cpuinfo_store_boot_cpu+0x54/0x64 [ 0.000000] smp_prepare_boot_cpu+0x2c/0x60 [ 0.000000] start_kernel+0x16c/0x574 [ 0.000000] Code: 17ffffc7 91010281 14000198 17ffffca (d4210000) This is addressed using a two-fold process: - Replace has_vhe() with is_kernel_in_hyp_mode(), which tests whether we are running at EL2. - Make CHOOSE_HYP_SYM() return an *undefined* symbol when compiled in the nVHE hypervisor, as we really should never use this helper in the nVHE-specific code. With this in place, we're back to a bootable kernel again. Fixes: b877e9849d41 ("KVM: arm64: Build hyp-entry.S separately for VHE/nVHE") Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 14:34:06 +00:00
#ifndef __KVM_NVHE_HYPERVISOR__
/*
* BIG FAT WARNINGS:
*
* - Don't be tempted to change the following is_kernel_in_hyp_mode()
* to has_vhe(). has_vhe() is implemented as a *final* capability,
* while this is used early at boot time, when the capabilities are
* not final yet....
*
* - Don't let the nVHE hypervisor have access to this, as it will
* pick the *wrong* symbol (yes, it runs at EL2...).
*/
#define CHOOSE_HYP_SYM(sym) (is_kernel_in_hyp_mode() ? CHOOSE_VHE_SYM(sym) \
KVM: arm64: Build hyp-entry.S separately for VHE/nVHE hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly shared between VHE/nVHE, therefore compile it under both VHE and nVHE build rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__. Adjust code which selects which KVM hyp vecs to install to choose the correct VHE/nVHE symbol. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-06-25 13:14:11 +00:00
: CHOOSE_NVHE_SYM(sym))
KVM: arm64: Don't use has_vhe() for CHOOSE_HYP_SYM() The recently introduced CHOOSE_HYP_SYM() macro picks one symbol or another, depending on whether the kernel run as a VHE hypervisor or not. For that, it uses the has_vhe() helper, which is itself implemented as a final capability. Unfortunately, __copy_hyp_vect_bpi now indirectly uses CHOOSE_HYP_SYM to get the __bp_harden_hyp_vecs symbol, using has_vhe() in the process. At this stage, the capability isn't final and things explode: [ 0.000000] ACPI: SRAT not present [ 0.000000] percpu: Embedded 34 pages/cpu s101264 r8192 d29808 u139264 [ 0.000000] Detected PIPT I-cache on CPU0 [ 0.000000] ------------[ cut here ]------------ [ 0.000000] kernel BUG at arch/arm64/include/asm/cpufeature.h:459! [ 0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-rc4-00080-gd630681366e5 #1388 [ 0.000000] pstate: 80000085 (Nzcv daIf -PAN -UAO BTYPE=--) [ 0.000000] pc : check_branch_predictor+0x3a4/0x408 [ 0.000000] lr : check_branch_predictor+0x2a4/0x408 [ 0.000000] sp : ffff800011693e90 [ 0.000000] x29: ffff800011693e90 x28: ffff8000116a1530 [ 0.000000] x27: ffff8000112c1008 x26: ffff800010ca6ff8 [ 0.000000] x25: ffff8000112c1000 x24: ffff8000116a1320 [ 0.000000] x23: 0000000000000000 x22: ffff8000112c1000 [ 0.000000] x21: ffff800010177120 x20: ffff8000116ae108 [ 0.000000] x19: 0000000000000000 x18: ffff800011965c90 [ 0.000000] x17: 0000000000022000 x16: 0000000000000003 [ 0.000000] x15: 00000000ffffffff x14: ffff8000118c3a38 [ 0.000000] x13: 0000000000000021 x12: 0000000000000022 [ 0.000000] x11: d37a6f4de9bd37a7 x10: 000000000000001d [ 0.000000] x9 : 0000000000000000 x8 : ffff800011f8dad8 [ 0.000000] x7 : ffff800011965ad0 x6 : 0000000000000003 [ 0.000000] x5 : 0000000000000000 x4 : 0000000000000000 [ 0.000000] x3 : 0000000000000100 x2 : 0000000000000004 [ 0.000000] x1 : ffff8000116ae148 x0 : 0000000000000000 [ 0.000000] Call trace: [ 0.000000] check_branch_predictor+0x3a4/0x408 [ 0.000000] update_cpu_capabilities+0x84/0x138 [ 0.000000] init_cpu_features+0x2c0/0x2d8 [ 0.000000] cpuinfo_store_boot_cpu+0x54/0x64 [ 0.000000] smp_prepare_boot_cpu+0x2c/0x60 [ 0.000000] start_kernel+0x16c/0x574 [ 0.000000] Code: 17ffffc7 91010281 14000198 17ffffca (d4210000) This is addressed using a two-fold process: - Replace has_vhe() with is_kernel_in_hyp_mode(), which tests whether we are running at EL2. - Make CHOOSE_HYP_SYM() return an *undefined* symbol when compiled in the nVHE hypervisor, as we really should never use this helper in the nVHE-specific code. With this in place, we're back to a bootable kernel again. Fixes: b877e9849d41 ("KVM: arm64: Build hyp-entry.S separately for VHE/nVHE") Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-07-07 14:34:06 +00:00
#else
/* The nVHE hypervisor shouldn't even try to access anything */
extern void *__nvhe_undefined_symbol;
#define CHOOSE_HYP_SYM(sym) __nvhe_undefined_symbol
#endif
KVM: arm64: Build hyp-entry.S separately for VHE/nVHE hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly shared between VHE/nVHE, therefore compile it under both VHE and nVHE build rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__. Adjust code which selects which KVM hyp vecs to install to choose the correct VHE/nVHE symbol. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-06-25 13:14:11 +00:00
/* Translate a kernel address @ptr into its equivalent linear mapping */
#define kvm_ksym_ref(ptr) \
arm64: KVM: Turn kvm_ksym_ref into a NOP on VHE When running with VHE, there is no need to translate kernel pointers to the EL2 memory space, since we're already there (and we have a much saner memory map to start with). Unfortunately, kvm_ksym_ref is getting in the way, and the first call into the "hypervisor" section is going to end up in fireworks, since we're now branching into nowhereland. Meh. A potential solution is to test if VHE is engaged or not, and only perform the translation in the negative case. With this in place, VHE is able to run again. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-03-18 17:25:59 +00:00
({ \
KVM: arm64: Build hyp-entry.S separately for VHE/nVHE hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly shared between VHE/nVHE, therefore compile it under both VHE and nVHE build rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__. Adjust code which selects which KVM hyp vecs to install to choose the correct VHE/nVHE symbol. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-06-25 13:14:11 +00:00
void *val = (ptr); \
arm64: KVM: Turn kvm_ksym_ref into a NOP on VHE When running with VHE, there is no need to translate kernel pointers to the EL2 memory space, since we're already there (and we have a much saner memory map to start with). Unfortunately, kvm_ksym_ref is getting in the way, and the first call into the "hypervisor" section is going to end up in fireworks, since we're now branching into nowhereland. Meh. A potential solution is to test if VHE is engaged or not, and only perform the translation in the negative case. With this in place, VHE is able to run again. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-03-18 17:25:59 +00:00
if (!is_kernel_in_hyp_mode()) \
KVM: arm64: Build hyp-entry.S separately for VHE/nVHE hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly shared between VHE/nVHE, therefore compile it under both VHE and nVHE build rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__. Adjust code which selects which KVM hyp vecs to install to choose the correct VHE/nVHE symbol. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-06-25 13:14:11 +00:00
val = lm_alias((ptr)); \
arm64: KVM: Turn kvm_ksym_ref into a NOP on VHE When running with VHE, there is no need to translate kernel pointers to the EL2 memory space, since we're already there (and we have a much saner memory map to start with). Unfortunately, kvm_ksym_ref is getting in the way, and the first call into the "hypervisor" section is going to end up in fireworks, since we're now branching into nowhereland. Meh. A potential solution is to test if VHE is engaged or not, and only perform the translation in the negative case. With this in place, VHE is able to run again. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-03-18 17:25:59 +00:00
val; \
})
KVM: arm64: Handle calls to prefixed hyp functions Once hyp functions are moved to a hyp object, they will have prefixed symbols. This change declares and gets the address of the prefixed version for calls to the hyp functions. To aid migration, the hyp functions that have not yet moved have their prefixed versions aliased to their non-prefixed version. This begins with all the hyp functions being listed and will reduce to none of them once the migration is complete. Signed-off-by: Andrew Scull <ascull@google.com> [David: Extracted kvm_call_hyp nVHE branches into own helper macros, added comments around symbol aliases.] Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-6-dbrazdil@google.com
2020-06-25 13:14:10 +00:00
#define kvm_ksym_ref_nvhe(sym) kvm_ksym_ref(kvm_nvhe_sym(sym))
arm64: kvm: deal with kernel symbols outside of linear mapping KVM on arm64 uses a fixed offset between the linear mapping at EL1 and the HYP mapping at EL2. Before we can move the kernel virtual mapping out of the linear mapping, we have to make sure that references to kernel symbols that are accessed via the HYP mapping are translated to their linear equivalent. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2016-02-16 12:52:39 +00:00
arm64: KVM: system register definitions for 64bit guests Define the saved/restored registers for 64bit guests. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-12-10 11:16:40 +00:00
struct kvm;
struct kvm_vcpu;
KVM: arm64: Factor out stage 2 page table data from struct kvm As we are about to reuse our stage 2 page table manipulation code for shadow stage 2 page tables in the context of nested virtualization, we are going to manage multiple stage 2 page tables for a single VM. This requires some pretty invasive changes to our data structures, which moves the vmid and pgd pointers into a separate structure and change pretty much all of our mmu code to operate on this structure instead. The new structure is called struct kvm_s2_mmu. There is no intended functional change by this patch alone. Reviewed-by: James Morse <james.morse@arm.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> [Designed data structure layout in collaboration] Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Co-developed-by: Marc Zyngier <maz@kernel.org> [maz: Moved the last_vcpu_ran down to the S2 MMU structure as well] Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-01-04 20:09:05 +00:00
struct kvm_s2_mmu;
arm64: KVM: system register definitions for 64bit guests Define the saved/restored registers for 64bit guests. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-12-10 11:16:40 +00:00
KVM: arm64: Move hyp-init.S to nVHE hyp-init.S contains the identity mapped initialisation code for the non-VHE code that runs at EL2. It is only used for non-VHE. Adjust code that calls into this to use the prefixed symbol name. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-8-dbrazdil@google.com
2020-06-25 13:14:12 +00:00
DECLARE_KVM_NVHE_SYM(__kvm_hyp_init);
KVM: arm64: Build hyp-entry.S separately for VHE/nVHE hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly shared between VHE/nVHE, therefore compile it under both VHE and nVHE build rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__. Adjust code which selects which KVM hyp vecs to install to choose the correct VHE/nVHE symbol. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-06-25 13:14:11 +00:00
DECLARE_KVM_HYP_SYM(__kvm_hyp_vector);
KVM: arm64: Move hyp-init.S to nVHE hyp-init.S contains the identity mapped initialisation code for the non-VHE code that runs at EL2. It is only used for non-VHE. Adjust code that calls into this to use the prefixed symbol name. Signed-off-by: Andrew Scull <ascull@google.com> Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-8-dbrazdil@google.com
2020-06-25 13:14:12 +00:00
#define __kvm_hyp_init CHOOSE_NVHE_SYM(__kvm_hyp_init)
KVM: arm64: Build hyp-entry.S separately for VHE/nVHE hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly shared between VHE/nVHE, therefore compile it under both VHE and nVHE build rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__. Adjust code which selects which KVM hyp vecs to install to choose the correct VHE/nVHE symbol. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com
2020-06-25 13:14:11 +00:00
#define __kvm_hyp_vector CHOOSE_HYP_SYM(__kvm_hyp_vector)
#ifdef CONFIG_KVM_INDIRECT_VECTORS
extern atomic_t arm64_el2_vector_last_slot;
DECLARE_KVM_HYP_SYM(__bp_harden_hyp_vecs);
#define __bp_harden_hyp_vecs CHOOSE_HYP_SYM(__bp_harden_hyp_vecs)
#endif
arm64: KVM: system register definitions for 64bit guests Define the saved/restored registers for 64bit guests. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-12-10 11:16:40 +00:00
extern void __kvm_flush_vm_context(void);
KVM: arm64: Use TTL hint in when invalidating stage-2 translations Since we often have a precise idea of the level we're dealing with when invalidating TLBs, we can provide it to as a hint to our invalidation helper. Reviewed-by: James Morse <james.morse@arm.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-01-02 12:34:25 +00:00
extern void __kvm_tlb_flush_vmid_ipa(struct kvm_s2_mmu *mmu, phys_addr_t ipa,
int level);
KVM: arm64: Factor out stage 2 page table data from struct kvm As we are about to reuse our stage 2 page table manipulation code for shadow stage 2 page tables in the context of nested virtualization, we are going to manage multiple stage 2 page tables for a single VM. This requires some pretty invasive changes to our data structures, which moves the vmid and pgd pointers into a separate structure and change pretty much all of our mmu code to operate on this structure instead. The new structure is called struct kvm_s2_mmu. There is no intended functional change by this patch alone. Reviewed-by: James Morse <james.morse@arm.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> [Designed data structure layout in collaboration] Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Co-developed-by: Marc Zyngier <maz@kernel.org> [maz: Moved the last_vcpu_ran down to the S2 MMU structure as well] Signed-off-by: Marc Zyngier <maz@kernel.org>
2019-01-04 20:09:05 +00:00
extern void __kvm_tlb_flush_vmid(struct kvm_s2_mmu *mmu);
extern void __kvm_tlb_flush_local_vmid(struct kvm_s2_mmu *mmu);
arm64: KVM: system register definitions for 64bit guests Define the saved/restored registers for 64bit guests. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-12-10 11:16:40 +00:00
KVM: arm64: Simplify __kvm_timer_set_cntvoff implementation Now that this function isn't constrained by the 32bit PCS, let's simplify it by taking a single 64bit offset instead of two 32bit parameters. Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-05-13 10:58:29 +00:00
extern void __kvm_timer_set_cntvoff(u64 cntvoff);
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 15:10:28 +00:00
KVM: arm64: Split hyp/switch.c to VHE/nVHE switch.c implements context-switching for KVM, with large parts shared between VHE/nVHE. These common routines are moved to a header file, VHE-specific code is moved to vhe/switch.c and nVHE-specific code is moved to nvhe/switch.c. Previously __kvm_vcpu_run needed a different symbol name for VHE/nVHE. This is cleaned up and the caller in arm.c simplified. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200625131420.71444-10-dbrazdil@google.com
2020-06-25 13:14:14 +00:00
extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
arm64: KVM: split GICv2 world switch from hyp code Move the GICv2 world switch code into its own file, and add the necessary indirection to the arm64 switch code. Also introduce a new type field to the vgic_params structure. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-06-21 10:57:56 +00:00
KVM: arm64: Clean up cpu_init_hyp_mode() Pull bits of code to the only place where it is used. Remove empty function __cpu_init_stage2(). Remove redundant has_vhe() check since this function is nVHE-only. No functional changes intended. Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200515152056.83158-1-dbrazdil@google.com
2020-05-15 15:20:56 +00:00
extern void __kvm_enable_ssbs(void);
KVM: ARM: vgic: add the GICv3 backend Introduce the support code for emulating a GICv2 on top of GICv3 hardware. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-07-12 14:15:23 +00:00
extern u64 __vgic_v3_get_ich_vtr_el2(void);
KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/put We don't have to save/restore the VMCR on every entry to/from the guest, since on GICv2 we can access the control interface from EL1 and on VHE systems with GICv3 we can access the control interface from KVM running in EL2. GICv3 systems without VHE becomes the rare case, which has to save/restore the register on each round trip. Note that userspace accesses may see out-of-date values if the VCPU is running while accessing the VGIC state via the KVM device API, but this is already the case and it is up to userspace to quiesce the CPUs before reading the CPU registers from the GIC for an up-to-date view. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2016-03-24 10:21:04 +00:00
extern u64 __vgic_v3_read_vmcr(void);
extern void __vgic_v3_write_vmcr(u32 vmcr);
arm64: KVM: vgic-v3: Reset LRs at boot time In order to let the GICv3 code be more lazy in the way it accesses the LRs, it is necessary to start with a clean slate. Let's reset the LRs on each CPU when the vgic is probed (which includes a round trip to EL2...). Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-03 15:43:58 +00:00
extern void __vgic_v3_init_lrs(void);
KVM: ARM: vgic: add the GICv3 backend Introduce the support code for emulating a GICv2 on top of GICv3 hardware. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2013-07-12 14:15:23 +00:00
KVM: arm: introduce kvm_arm_init/setup/clear_debug This is a precursor for later patches which will need to do more to setup debug state before entering the hyp.S switch code. The existing functionality for setting mdcr_el2 has been moved out of hyp.S and now uses the value kept in vcpu->arch.mdcr_el2. As the assembler used to previously mask and preserve MDCR_EL2.HPMN I've had to add a mechanism to save the value of mdcr_el2 as a per-cpu variable during the initialisation code. The kernel never sets this number so we are assuming the bootcode has set up the correct value here. This also moves the conditional setting of the TDA bit from the hyp code into the C code which is currently used for the lazy debug register context switch code. Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-07-07 16:29:56 +00:00
extern u32 __kvm_get_mdcr_el2(void);
arm64: kvm: Modernize __smccc_workaround_1_smc_start annotations In an effort to clarify and simplify the annotation of assembly functions in the kernel new macros have been introduced. These replace ENTRY and ENDPROC with separate annotations for standard C callable functions, data and code with different calling conventions. Using these for __smccc_workaround_1_smc is more involved than for most symbols as this symbol is annotated quite unusually, rather than just have the explicit symbol we define _start and _end symbols which we then use to compute the length. This does not play at all nicely with the new style macros. Instead define a constant for the size of the function and use that in both the C code and for .org based size checks in the assembly code. Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Marc Zyngier <maz@kernel.org>
2020-02-18 19:58:39 +00:00
extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ];
KVM: arm64: Move hyp_symbol_addr() to kvm_asm.h Recent refactoring of the arm64 code make it awkward to have hyp_symbol_addr() in kvm_mmu.h. Instead, move it next to its main user, which is __hyp_this_cpu_ptr(). Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-10 15:27:46 +00:00
/*
* Obtain the PC-relative address of a kernel symbol
* s: symbol
*
* The goal of this macro is to return a symbol's address based on a
* PC-relative computation, as opposed to a loading the VA from a
* constant pool or something similar. This works well for HYP, as an
* absolute VA is guaranteed to be wrong. Only use this if trying to
* obtain the address of a symbol (i.e. not something you obtained by
* following a pointer).
*/
#define hyp_symbol_addr(s) \
({ \
typeof(s) *addr; \
asm("adrp %0, %1\n" \
"add %0, %0, :lo12:%1\n" \
: "=r" (addr) : "S" (&s)); \
addr; \
})
KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr Sparse complains that __hyp_this_cpu_ptr() returns something that is flagged noderef and not in the correct address space (both being the result of the __percpu annotation). Pretend that __hyp_this_cpu_ptr() knows what it is doing by forcefully casting the pointer with __kernel __force. Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-07 09:55:28 +00:00
/*
* Home-grown __this_cpu_{ptr,read} variants that always work at HYP,
* provided that sym is really a *symbol* and not a pointer obtained from
* a data structure. As for SHIFT_PERCPU_PTR(), the creative casting keeps
* sparse quiet.
*/
arm64: KVM: Add HYP per-cpu accessors As we're going to require to access per-cpu variables at EL2, let's craft the minimum set of accessors required to implement reading a per-cpu variable, relying on tpidr_el2 to contain the per-cpu offset. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-29 12:11:15 +00:00
#define __hyp_this_cpu_ptr(sym) \
({ \
KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr Sparse complains that __hyp_this_cpu_ptr() returns something that is flagged noderef and not in the correct address space (both being the result of the __percpu annotation). Pretend that __hyp_this_cpu_ptr() knows what it is doing by forcefully casting the pointer with __kernel __force. Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-07 09:55:28 +00:00
void *__ptr; \
__verify_pcpu_ptr(&sym); \
__ptr = hyp_symbol_addr(sym); \
arm64: KVM: Add HYP per-cpu accessors As we're going to require to access per-cpu variables at EL2, let's craft the minimum set of accessors required to implement reading a per-cpu variable, relying on tpidr_el2 to contain the per-cpu offset. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-29 12:11:15 +00:00
__ptr += read_sysreg(tpidr_el2); \
KVM: arm64: Stop sparse from moaning at __hyp_this_cpu_ptr Sparse complains that __hyp_this_cpu_ptr() returns something that is flagged noderef and not in the correct address space (both being the result of the __percpu annotation). Pretend that __hyp_this_cpu_ptr() knows what it is doing by forcefully casting the pointer with __kernel __force. Signed-off-by: Marc Zyngier <maz@kernel.org>
2020-06-07 09:55:28 +00:00
(typeof(sym) __kernel __force *)__ptr; \
arm64: KVM: Add HYP per-cpu accessors As we're going to require to access per-cpu variables at EL2, let's craft the minimum set of accessors required to implement reading a per-cpu variable, relying on tpidr_el2 to contain the per-cpu offset. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-29 12:11:15 +00:00
})
#define __hyp_this_cpu_read(sym) \
({ \
*__hyp_this_cpu_ptr(sym); \
})
KVM: arm64: Survive synchronous exceptions caused by AT instructions KVM doesn't expect any synchronous exceptions when executing, any such exception leads to a panic(). AT instructions access the guest page tables, and can cause a synchronous external abort to be taken. The arm-arm is unclear on what should happen if the guest has configured the hardware update of the access-flag, and a memory type in TCR_EL1 that does not support atomic operations. B2.2.6 "Possible implementation restrictions on using atomic instructions" from DDI0487F.a lists synchronous external abort as a possible behaviour of atomic instructions that target memory that isn't writeback cacheable, but the page table walker may behave differently. Make KVM robust to synchronous exceptions caused by AT instructions. Add a get_user() style helper for AT instructions that returns -EFAULT if an exception was generated. While KVM's version of the exception table mixes synchronous and asynchronous exceptions, only one of these can occur at each location. Re-enter the guest when the AT instructions take an exception on the assumption the guest will take the same exception. This isn't guaranteed to make forward progress, as the AT instructions may always walk the page tables, but guest execution may use the translation cached in the TLB. This isn't a problem, as since commit 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending"), KVM will return to the host to process IRQs allowing the rest of the system to keep running. Cc: stable@vger.kernel.org # <v5.3: 5dcd0fdbb492 ("KVM: arm64: Defer guest entry when an asynchronous exception is pending") Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-21 14:07:06 +00:00
#define __KVM_EXTABLE(from, to) \
" .pushsection __kvm_ex_table, \"a\"\n" \
" .align 3\n" \
" .long (" #from " - .), (" #to " - .)\n" \
" .popsection\n"
#define __kvm_at(at_op, addr) \
( { \
int __kvm_at_err = 0; \
u64 spsr, elr; \
asm volatile( \
" mrs %1, spsr_el2\n" \
" mrs %2, elr_el2\n" \
"1: at "at_op", %3\n" \
" isb\n" \
" b 9f\n" \
"2: msr spsr_el2, %1\n" \
" msr elr_el2, %2\n" \
" mov %w0, %4\n" \
"9:\n" \
__KVM_EXTABLE(1b, 2b) \
: "+r" (__kvm_at_err), "=&r" (spsr), "=&r" (elr) \
: "r" (addr), "i" (-EFAULT)); \
__kvm_at_err; \
} )
KVM: arm64: Avoid storing the vcpu pointer on the stack We already have the percpu area for the host cpu state, which points to the VCPU, so there's no need to store the VCPU pointer on the stack on every context switch. We can be a little more clever and just use tpidr_el2 for the percpu offset and load the VCPU pointer from the host context. This has the benefit of being able to retrieve the host context even when our stack is corrupted, and it has a potential performance benefit because we trade a store plus a load for an mrs and a load on a round trip to the guest. This does require us to calculate the percpu offset without including the offset from the kernel mapping of the percpu array to the linear mapping of the array (which is what we store in tpidr_el1), because a PC-relative generated address in EL2 is already giving us the hyp alias of the linear mapping of a kernel address. We do this in __cpu_init_hyp_mode() by using kvm_ksym_ref(). The code that accesses ESR_EL2 was previously using an alternative to use the _EL1 accessor on VHE systems, but this was actually unnecessary as the _EL1 accessor aliases the ESR_EL2 register on VHE, and the _EL2 accessor does the same thing on both systems. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-08 15:01:56 +00:00
#else /* __ASSEMBLY__ */
arm64: KVM: Add HYP per-cpu accessors As we're going to require to access per-cpu variables at EL2, let's craft the minimum set of accessors required to implement reading a per-cpu variable, relying on tpidr_el2 to contain the per-cpu offset. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-29 12:11:15 +00:00
.macro hyp_adr_this_cpu reg, sym, tmp
adr_l \reg, \sym
KVM: arm64: Avoid storing the vcpu pointer on the stack We already have the percpu area for the host cpu state, which points to the VCPU, so there's no need to store the VCPU pointer on the stack on every context switch. We can be a little more clever and just use tpidr_el2 for the percpu offset and load the VCPU pointer from the host context. This has the benefit of being able to retrieve the host context even when our stack is corrupted, and it has a potential performance benefit because we trade a store plus a load for an mrs and a load on a round trip to the guest. This does require us to calculate the percpu offset without including the offset from the kernel mapping of the percpu array to the linear mapping of the array (which is what we store in tpidr_el1), because a PC-relative generated address in EL2 is already giving us the hyp alias of the linear mapping of a kernel address. We do this in __cpu_init_hyp_mode() by using kvm_ksym_ref(). The code that accesses ESR_EL2 was previously using an alternative to use the _EL1 accessor on VHE systems, but this was actually unnecessary as the _EL1 accessor aliases the ESR_EL2 register on VHE, and the _EL2 accessor does the same thing on both systems. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-08 15:01:56 +00:00
mrs \tmp, tpidr_el2
add \reg, \reg, \tmp
.endm
arm64: KVM: Add HYP per-cpu accessors As we're going to require to access per-cpu variables at EL2, let's craft the minimum set of accessors required to implement reading a per-cpu variable, relying on tpidr_el2 to contain the per-cpu offset. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-29 12:11:15 +00:00
.macro hyp_ldr_this_cpu reg, sym, tmp
adr_l \reg, \sym
mrs \tmp, tpidr_el2
ldr \reg, [\reg, \tmp]
.endm
.macro get_host_ctxt reg, tmp
arm64: KVM: Encapsulate kvm_cpu_context in kvm_host_data The virt/arm core allocates a kvm_cpu_context_t percpu, at present this is a typedef to kvm_cpu_context and is used to store host cpu context. The kvm_cpu_context structure is also used elsewhere to hold vcpu context. In order to use the percpu to hold additional future host information we encapsulate kvm_cpu_context in a new structure and rename the typedef and percpu to match. Signed-off-by: Andrew Murray <andrew.murray@arm.com> Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-04-09 19:22:11 +00:00
hyp_adr_this_cpu \reg, kvm_host_data, \tmp
add \reg, \reg, #HOST_DATA_CONTEXT
arm64: KVM: Add HYP per-cpu accessors As we're going to require to access per-cpu variables at EL2, let's craft the minimum set of accessors required to implement reading a per-cpu variable, relying on tpidr_el2 to contain the per-cpu offset. Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-29 12:11:15 +00:00
.endm
KVM: arm64: Avoid storing the vcpu pointer on the stack We already have the percpu area for the host cpu state, which points to the VCPU, so there's no need to store the VCPU pointer on the stack on every context switch. We can be a little more clever and just use tpidr_el2 for the percpu offset and load the VCPU pointer from the host context. This has the benefit of being able to retrieve the host context even when our stack is corrupted, and it has a potential performance benefit because we trade a store plus a load for an mrs and a load on a round trip to the guest. This does require us to calculate the percpu offset without including the offset from the kernel mapping of the percpu array to the linear mapping of the array (which is what we store in tpidr_el1), because a PC-relative generated address in EL2 is already giving us the hyp alias of the linear mapping of a kernel address. We do this in __cpu_init_hyp_mode() by using kvm_ksym_ref(). The code that accesses ESR_EL2 was previously using an alternative to use the _EL1 accessor on VHE systems, but this was actually unnecessary as the _EL1 accessor aliases the ESR_EL2 register on VHE, and the _EL2 accessor does the same thing on both systems. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-10-08 15:01:56 +00:00
.macro get_vcpu_ptr vcpu, ctxt
get_host_ctxt \ctxt, \vcpu
ldr \vcpu, [\ctxt, #HOST_CONTEXT_VCPU]
.endm
KVM: arm64: Add kvm_extable for vaxorcism code KVM has a one instruction window where it will allow an SError exception to be consumed by the hypervisor without treating it as a hypervisor bug. This is used to consume asynchronous external abort that were caused by the guest. As we are about to add another location that survives unexpected exceptions, generalise this code to make it behave like the host's extable. KVM's version has to be mapped to EL2 to be accessible on nVHE systems. The SError vaxorcism code is a one instruction window, so has two entries in the extable. Because the KVM code is copied for VHE and nVHE, we end up with four entries, half of which correspond with code that isn't mapped. Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-21 14:07:05 +00:00
/*
* KVM extable for unexpected exceptions.
* In the same format _asm_extable, but output to a different section so that
* it can be mapped to EL2. The KVM version is not sorted. The caller must
* ensure:
* x18 has the hypervisor value to allow any Shadow-Call-Stack instrumented
* code to write to it, and that SPSR_EL2 and ELR_EL2 are restored by the fixup.
*/
.macro _kvm_extable, from, to
.pushsection __kvm_ex_table, "a"
.align 3
.long (\from - .), (\to - .)
.popsection
.endm
arm64: KVM: system register definitions for 64bit guests Define the saved/restored registers for 64bit guests. Reviewed-by: Christopher Covington <cov@codeaurora.org> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2012-12-10 11:16:40 +00:00
#endif
#endif /* __ARM_KVM_ASM_H__ */
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