mmu.h (986c6f7c3fc855032f3457a5a1b7fbcc09c375bb) mmu.h (d6174299365ddbbf491620c0b8c5ca1a6ef2eea5)
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __KVM_X86_MMU_H
3#define __KVM_X86_MMU_H
4
5#include <linux/kvm_host.h>
6#include "kvm_cache_regs.h"
7#include "cpuid.h"
8

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43#define PT64_ROOT_4LEVEL 4
44#define PT32_ROOT_LEVEL 2
45#define PT32E_ROOT_LEVEL 3
46
47#define KVM_MMU_CR4_ROLE_BITS (X86_CR4_PSE | X86_CR4_PAE | X86_CR4_LA57 | \
48 X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE)
49
50#define KVM_MMU_CR0_ROLE_BITS (X86_CR0_PG | X86_CR0_WP)
1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __KVM_X86_MMU_H
3#define __KVM_X86_MMU_H
4
5#include <linux/kvm_host.h>
6#include "kvm_cache_regs.h"
7#include "cpuid.h"
8

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43#define PT64_ROOT_4LEVEL 4
44#define PT32_ROOT_LEVEL 2
45#define PT32E_ROOT_LEVEL 3
46
47#define KVM_MMU_CR4_ROLE_BITS (X86_CR4_PSE | X86_CR4_PAE | X86_CR4_LA57 | \
48 X86_CR4_SMEP | X86_CR4_SMAP | X86_CR4_PKE)
49
50#define KVM_MMU_CR0_ROLE_BITS (X86_CR0_PG | X86_CR0_WP)
51#define KVM_MMU_EFER_ROLE_BITS (EFER_LME | EFER_NX)
51
52static __always_inline u64 rsvd_bits(int s, int e)
53{
54 BUILD_BUG_ON(__builtin_constant_p(e) && __builtin_constant_p(s) && e < s);
55
56 if (__builtin_constant_p(e))
57 BUILD_BUG_ON(e > 63);
58 else

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198#ifdef CONFIG_RETPOLINE
199 if (fault.is_tdp)
200 return kvm_tdp_page_fault(vcpu, &fault);
201#endif
202 return vcpu->arch.mmu->page_fault(vcpu, &fault);
203}
204
205/*
52
53static __always_inline u64 rsvd_bits(int s, int e)
54{
55 BUILD_BUG_ON(__builtin_constant_p(e) && __builtin_constant_p(s) && e < s);
56
57 if (__builtin_constant_p(e))
58 BUILD_BUG_ON(e > 63);
59 else

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199#ifdef CONFIG_RETPOLINE
200 if (fault.is_tdp)
201 return kvm_tdp_page_fault(vcpu, &fault);
202#endif
203 return vcpu->arch.mmu->page_fault(vcpu, &fault);
204}
205
206/*
206 * Currently, we have two sorts of write-protection, a) the first one
207 * write-protects guest page to sync the guest modification, b) another one is
208 * used to sync dirty bitmap when we do KVM_GET_DIRTY_LOG. The differences
209 * between these two sorts are:
210 * 1) the first case clears MMU-writable bit.
211 * 2) the first case requires flushing tlb immediately avoiding corrupting
212 * shadow page table between all vcpus so it should be in the protection of
213 * mmu-lock. And the another case does not need to flush tlb until returning
214 * the dirty bitmap to userspace since it only write-protects the page
215 * logged in the bitmap, that means the page in the dirty bitmap is not
216 * missed, so it can flush tlb out of mmu-lock.
217 *
218 * So, there is the problem: the first case can meet the corrupted tlb caused
219 * by another case which write-protects pages but without flush tlb
220 * immediately. In order to making the first case be aware this problem we let
221 * it flush tlb if we try to write-protect a spte whose MMU-writable bit
222 * is set, it works since another case never touches MMU-writable bit.
223 *
224 * Anyway, whenever a spte is updated (only permission and status bits are
225 * changed) we need to check whether the spte with MMU-writable becomes
226 * readonly, if that happens, we need to flush tlb. Fortunately,
227 * mmu_spte_update() has already handled it perfectly.
228 *
229 * The rules to use MMU-writable and PT_WRITABLE_MASK:
230 * - if we want to see if it has writable tlb entry or if the spte can be
231 * writable on the mmu mapping, check MMU-writable, this is the most
232 * case, otherwise
233 * - if we fix page fault on the spte or do write-protection by dirty logging,
234 * check PT_WRITABLE_MASK.
235 *
236 * TODO: introduce APIs to split these two cases.
237 */
238static inline bool is_writable_pte(unsigned long pte)
239{
240 return pte & PT_WRITABLE_MASK;
241}
242
243/*
244 * Check if a given access (described through the I/D, W/R and U/S bits of a
245 * page fault error code pfec) causes a permission fault with the given PTE
246 * access rights (in ACC_* format).
247 *
248 * Return zero if the access does not fault; return the page fault error code
249 * if the access faults.
250 */
251static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,

--- 117 unchanged lines hidden --- 		207 * Check if a given access (described through the I/D, W/R and U/S bits of a
208 * page fault error code pfec) causes a permission fault with the given PTE
209 * access rights (in ACC_* format).
210 *
211 * Return zero if the access does not fault; return the page fault error code
212 * if the access faults.
213 */
214static inline u8 permission_fault(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu,

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