mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-25 03:55:09 +08:00
9d4655da1a
Use gfn_t instead of u64 for kvm_flush_remote_tlbs_range()'s parameters, since gfn_t is the standard type for GFNs throughout KVM. Opportunistically rename pages to nr_pages to make its role even more obvious. No functional change intended. Signed-off-by: David Matlack <dmatlack@google.com> Link: https://lore.kernel.org/r/20230126184025.2294823-6-dmatlack@google.com [sean: convert pages to gfn_t too, and rename] Signed-off-by: Sean Christopherson <seanjc@google.com>
353 lines
11 KiB
C
353 lines
11 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef __KVM_X86_MMU_INTERNAL_H
|
|
#define __KVM_X86_MMU_INTERNAL_H
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/kvm_host.h>
|
|
#include <asm/kvm_host.h>
|
|
|
|
#undef MMU_DEBUG
|
|
|
|
#ifdef MMU_DEBUG
|
|
extern bool dbg;
|
|
|
|
#define pgprintk(x...) do { if (dbg) printk(x); } while (0)
|
|
#define rmap_printk(fmt, args...) do { if (dbg) printk("%s: " fmt, __func__, ## args); } while (0)
|
|
#define MMU_WARN_ON(x) WARN_ON(x)
|
|
#else
|
|
#define pgprintk(x...) do { } while (0)
|
|
#define rmap_printk(x...) do { } while (0)
|
|
#define MMU_WARN_ON(x) do { } while (0)
|
|
#endif
|
|
|
|
/* Page table builder macros common to shadow (host) PTEs and guest PTEs. */
|
|
#define __PT_LEVEL_SHIFT(level, bits_per_level) \
|
|
(PAGE_SHIFT + ((level) - 1) * (bits_per_level))
|
|
#define __PT_INDEX(address, level, bits_per_level) \
|
|
(((address) >> __PT_LEVEL_SHIFT(level, bits_per_level)) & ((1 << (bits_per_level)) - 1))
|
|
|
|
#define __PT_LVL_ADDR_MASK(base_addr_mask, level, bits_per_level) \
|
|
((base_addr_mask) & ~((1ULL << (PAGE_SHIFT + (((level) - 1) * (bits_per_level)))) - 1))
|
|
|
|
#define __PT_LVL_OFFSET_MASK(base_addr_mask, level, bits_per_level) \
|
|
((base_addr_mask) & ((1ULL << (PAGE_SHIFT + (((level) - 1) * (bits_per_level)))) - 1))
|
|
|
|
#define __PT_ENT_PER_PAGE(bits_per_level) (1 << (bits_per_level))
|
|
|
|
/*
|
|
* Unlike regular MMU roots, PAE "roots", a.k.a. PDPTEs/PDPTRs, have a PRESENT
|
|
* bit, and thus are guaranteed to be non-zero when valid. And, when a guest
|
|
* PDPTR is !PRESENT, its corresponding PAE root cannot be set to INVALID_PAGE,
|
|
* as the CPU would treat that as PRESENT PDPTR with reserved bits set. Use
|
|
* '0' instead of INVALID_PAGE to indicate an invalid PAE root.
|
|
*/
|
|
#define INVALID_PAE_ROOT 0
|
|
#define IS_VALID_PAE_ROOT(x) (!!(x))
|
|
|
|
typedef u64 __rcu *tdp_ptep_t;
|
|
|
|
struct kvm_mmu_page {
|
|
/*
|
|
* Note, "link" through "spt" fit in a single 64 byte cache line on
|
|
* 64-bit kernels, keep it that way unless there's a reason not to.
|
|
*/
|
|
struct list_head link;
|
|
struct hlist_node hash_link;
|
|
|
|
bool tdp_mmu_page;
|
|
bool unsync;
|
|
u8 mmu_valid_gen;
|
|
|
|
/*
|
|
* The shadow page can't be replaced by an equivalent huge page
|
|
* because it is being used to map an executable page in the guest
|
|
* and the NX huge page mitigation is enabled.
|
|
*/
|
|
bool nx_huge_page_disallowed;
|
|
|
|
/*
|
|
* The following two entries are used to key the shadow page in the
|
|
* hash table.
|
|
*/
|
|
union kvm_mmu_page_role role;
|
|
gfn_t gfn;
|
|
|
|
u64 *spt;
|
|
|
|
/*
|
|
* Stores the result of the guest translation being shadowed by each
|
|
* SPTE. KVM shadows two types of guest translations: nGPA -> GPA
|
|
* (shadow EPT/NPT) and GVA -> GPA (traditional shadow paging). In both
|
|
* cases the result of the translation is a GPA and a set of access
|
|
* constraints.
|
|
*
|
|
* The GFN is stored in the upper bits (PAGE_SHIFT) and the shadowed
|
|
* access permissions are stored in the lower bits. Note, for
|
|
* convenience and uniformity across guests, the access permissions are
|
|
* stored in KVM format (e.g. ACC_EXEC_MASK) not the raw guest format.
|
|
*/
|
|
u64 *shadowed_translation;
|
|
|
|
/* Currently serving as active root */
|
|
union {
|
|
int root_count;
|
|
refcount_t tdp_mmu_root_count;
|
|
};
|
|
unsigned int unsync_children;
|
|
union {
|
|
struct kvm_rmap_head parent_ptes; /* rmap pointers to parent sptes */
|
|
tdp_ptep_t ptep;
|
|
};
|
|
union {
|
|
DECLARE_BITMAP(unsync_child_bitmap, 512);
|
|
struct {
|
|
struct work_struct tdp_mmu_async_work;
|
|
void *tdp_mmu_async_data;
|
|
};
|
|
};
|
|
|
|
/*
|
|
* Tracks shadow pages that, if zapped, would allow KVM to create an NX
|
|
* huge page. A shadow page will have nx_huge_page_disallowed set but
|
|
* not be on the list if a huge page is disallowed for other reasons,
|
|
* e.g. because KVM is shadowing a PTE at the same gfn, the memslot
|
|
* isn't properly aligned, etc...
|
|
*/
|
|
struct list_head possible_nx_huge_page_link;
|
|
#ifdef CONFIG_X86_32
|
|
/*
|
|
* Used out of the mmu-lock to avoid reading spte values while an
|
|
* update is in progress; see the comments in __get_spte_lockless().
|
|
*/
|
|
int clear_spte_count;
|
|
#endif
|
|
|
|
/* Number of writes since the last time traversal visited this page. */
|
|
atomic_t write_flooding_count;
|
|
|
|
#ifdef CONFIG_X86_64
|
|
/* Used for freeing the page asynchronously if it is a TDP MMU page. */
|
|
struct rcu_head rcu_head;
|
|
#endif
|
|
};
|
|
|
|
extern struct kmem_cache *mmu_page_header_cache;
|
|
|
|
static inline int kvm_mmu_role_as_id(union kvm_mmu_page_role role)
|
|
{
|
|
return role.smm ? 1 : 0;
|
|
}
|
|
|
|
static inline int kvm_mmu_page_as_id(struct kvm_mmu_page *sp)
|
|
{
|
|
return kvm_mmu_role_as_id(sp->role);
|
|
}
|
|
|
|
static inline bool kvm_mmu_page_ad_need_write_protect(struct kvm_mmu_page *sp)
|
|
{
|
|
/*
|
|
* When using the EPT page-modification log, the GPAs in the CPU dirty
|
|
* log would come from L2 rather than L1. Therefore, we need to rely
|
|
* on write protection to record dirty pages, which bypasses PML, since
|
|
* writes now result in a vmexit. Note, the check on CPU dirty logging
|
|
* being enabled is mandatory as the bits used to denote WP-only SPTEs
|
|
* are reserved for PAE paging (32-bit KVM).
|
|
*/
|
|
return kvm_x86_ops.cpu_dirty_log_size && sp->role.guest_mode;
|
|
}
|
|
|
|
static inline gfn_t gfn_round_for_level(gfn_t gfn, int level)
|
|
{
|
|
return gfn & -KVM_PAGES_PER_HPAGE(level);
|
|
}
|
|
|
|
int mmu_try_to_unsync_pages(struct kvm *kvm, const struct kvm_memory_slot *slot,
|
|
gfn_t gfn, bool can_unsync, bool prefetch);
|
|
|
|
void kvm_mmu_gfn_disallow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
|
|
void kvm_mmu_gfn_allow_lpage(const struct kvm_memory_slot *slot, gfn_t gfn);
|
|
bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,
|
|
struct kvm_memory_slot *slot, u64 gfn,
|
|
int min_level);
|
|
|
|
void kvm_flush_remote_tlbs_range(struct kvm *kvm, gfn_t start_gfn,
|
|
gfn_t nr_pages);
|
|
|
|
/* Flush the given page (huge or not) of guest memory. */
|
|
static inline void kvm_flush_remote_tlbs_gfn(struct kvm *kvm, gfn_t gfn, int level)
|
|
{
|
|
kvm_flush_remote_tlbs_range(kvm, gfn_round_for_level(gfn, level),
|
|
KVM_PAGES_PER_HPAGE(level));
|
|
}
|
|
|
|
unsigned int pte_list_count(struct kvm_rmap_head *rmap_head);
|
|
|
|
extern int nx_huge_pages;
|
|
static inline bool is_nx_huge_page_enabled(struct kvm *kvm)
|
|
{
|
|
return READ_ONCE(nx_huge_pages) && !kvm->arch.disable_nx_huge_pages;
|
|
}
|
|
|
|
struct kvm_page_fault {
|
|
/* arguments to kvm_mmu_do_page_fault. */
|
|
const gpa_t addr;
|
|
const u32 error_code;
|
|
const bool prefetch;
|
|
|
|
/* Derived from error_code. */
|
|
const bool exec;
|
|
const bool write;
|
|
const bool present;
|
|
const bool rsvd;
|
|
const bool user;
|
|
|
|
/* Derived from mmu and global state. */
|
|
const bool is_tdp;
|
|
const bool nx_huge_page_workaround_enabled;
|
|
|
|
/*
|
|
* Whether a >4KB mapping can be created or is forbidden due to NX
|
|
* hugepages.
|
|
*/
|
|
bool huge_page_disallowed;
|
|
|
|
/*
|
|
* Maximum page size that can be created for this fault; input to
|
|
* FNAME(fetch), direct_map() and kvm_tdp_mmu_map().
|
|
*/
|
|
u8 max_level;
|
|
|
|
/*
|
|
* Page size that can be created based on the max_level and the
|
|
* page size used by the host mapping.
|
|
*/
|
|
u8 req_level;
|
|
|
|
/*
|
|
* Page size that will be created based on the req_level and
|
|
* huge_page_disallowed.
|
|
*/
|
|
u8 goal_level;
|
|
|
|
/* Shifted addr, or result of guest page table walk if addr is a gva. */
|
|
gfn_t gfn;
|
|
|
|
/* The memslot containing gfn. May be NULL. */
|
|
struct kvm_memory_slot *slot;
|
|
|
|
/* Outputs of kvm_faultin_pfn. */
|
|
unsigned long mmu_seq;
|
|
kvm_pfn_t pfn;
|
|
hva_t hva;
|
|
bool map_writable;
|
|
|
|
/*
|
|
* Indicates the guest is trying to write a gfn that contains one or
|
|
* more of the PTEs used to translate the write itself, i.e. the access
|
|
* is changing its own translation in the guest page tables.
|
|
*/
|
|
bool write_fault_to_shadow_pgtable;
|
|
};
|
|
|
|
int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
|
|
|
|
/*
|
|
* Return values of handle_mmio_page_fault(), mmu.page_fault(), fast_page_fault(),
|
|
* and of course kvm_mmu_do_page_fault().
|
|
*
|
|
* RET_PF_CONTINUE: So far, so good, keep handling the page fault.
|
|
* RET_PF_RETRY: let CPU fault again on the address.
|
|
* RET_PF_EMULATE: mmio page fault, emulate the instruction directly.
|
|
* RET_PF_INVALID: the spte is invalid, let the real page fault path update it.
|
|
* RET_PF_FIXED: The faulting entry has been fixed.
|
|
* RET_PF_SPURIOUS: The faulting entry was already fixed, e.g. by another vCPU.
|
|
*
|
|
* Any names added to this enum should be exported to userspace for use in
|
|
* tracepoints via TRACE_DEFINE_ENUM() in mmutrace.h
|
|
*
|
|
* Note, all values must be greater than or equal to zero so as not to encroach
|
|
* on -errno return values. Somewhat arbitrarily use '0' for CONTINUE, which
|
|
* will allow for efficient machine code when checking for CONTINUE, e.g.
|
|
* "TEST %rax, %rax, JNZ", as all "stop!" values are non-zero.
|
|
*/
|
|
enum {
|
|
RET_PF_CONTINUE = 0,
|
|
RET_PF_RETRY,
|
|
RET_PF_EMULATE,
|
|
RET_PF_INVALID,
|
|
RET_PF_FIXED,
|
|
RET_PF_SPURIOUS,
|
|
};
|
|
|
|
static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
|
|
u32 err, bool prefetch, int *emulation_type)
|
|
{
|
|
struct kvm_page_fault fault = {
|
|
.addr = cr2_or_gpa,
|
|
.error_code = err,
|
|
.exec = err & PFERR_FETCH_MASK,
|
|
.write = err & PFERR_WRITE_MASK,
|
|
.present = err & PFERR_PRESENT_MASK,
|
|
.rsvd = err & PFERR_RSVD_MASK,
|
|
.user = err & PFERR_USER_MASK,
|
|
.prefetch = prefetch,
|
|
.is_tdp = likely(vcpu->arch.mmu->page_fault == kvm_tdp_page_fault),
|
|
.nx_huge_page_workaround_enabled =
|
|
is_nx_huge_page_enabled(vcpu->kvm),
|
|
|
|
.max_level = KVM_MAX_HUGEPAGE_LEVEL,
|
|
.req_level = PG_LEVEL_4K,
|
|
.goal_level = PG_LEVEL_4K,
|
|
};
|
|
int r;
|
|
|
|
if (vcpu->arch.mmu->root_role.direct) {
|
|
fault.gfn = fault.addr >> PAGE_SHIFT;
|
|
fault.slot = kvm_vcpu_gfn_to_memslot(vcpu, fault.gfn);
|
|
}
|
|
|
|
/*
|
|
* Async #PF "faults", a.k.a. prefetch faults, are not faults from the
|
|
* guest perspective and have already been counted at the time of the
|
|
* original fault.
|
|
*/
|
|
if (!prefetch)
|
|
vcpu->stat.pf_taken++;
|
|
|
|
if (IS_ENABLED(CONFIG_RETPOLINE) && fault.is_tdp)
|
|
r = kvm_tdp_page_fault(vcpu, &fault);
|
|
else
|
|
r = vcpu->arch.mmu->page_fault(vcpu, &fault);
|
|
|
|
if (fault.write_fault_to_shadow_pgtable && emulation_type)
|
|
*emulation_type |= EMULTYPE_WRITE_PF_TO_SP;
|
|
|
|
/*
|
|
* Similar to above, prefetch faults aren't truly spurious, and the
|
|
* async #PF path doesn't do emulation. Do count faults that are fixed
|
|
* by the async #PF handler though, otherwise they'll never be counted.
|
|
*/
|
|
if (r == RET_PF_FIXED)
|
|
vcpu->stat.pf_fixed++;
|
|
else if (prefetch)
|
|
;
|
|
else if (r == RET_PF_EMULATE)
|
|
vcpu->stat.pf_emulate++;
|
|
else if (r == RET_PF_SPURIOUS)
|
|
vcpu->stat.pf_spurious++;
|
|
return r;
|
|
}
|
|
|
|
int kvm_mmu_max_mapping_level(struct kvm *kvm,
|
|
const struct kvm_memory_slot *slot, gfn_t gfn,
|
|
int max_level);
|
|
void kvm_mmu_hugepage_adjust(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);
|
|
void disallowed_hugepage_adjust(struct kvm_page_fault *fault, u64 spte, int cur_level);
|
|
|
|
void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc);
|
|
|
|
void track_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp);
|
|
void untrack_possible_nx_huge_page(struct kvm *kvm, struct kvm_mmu_page *sp);
|
|
|
|
#endif /* __KVM_X86_MMU_INTERNAL_H */
|