linux/arch/x86/kvm/mmu/mmu_internal.h
Sean Christopherson ce92ef7604 KVM: x86/mmu: Use shadow page role to detect PML-unfriendly pages for L2
Rework make_spte() to query the shadow page's role, specifically whether
or not it's a guest_mode page, a.k.a. a page for L2, when determining if
the SPTE is compatible with PML.  This eliminates a dependency on @vcpu,
with a future goal of being able to create SPTEs without a specific vCPU.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-12-08 04:24:41 -05:00

164 lines
5.1 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
/*
* 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))
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;
bool lpage_disallowed; /* Can't be replaced by an equiv large page */
/*
* 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;
/* hold the gfn of each spte inside spt */
gfn_t *gfns;
/* Currently serving as active root */
union {
int root_count;
refcount_t tdp_mmu_root_count;
};
unsigned int unsync_children;
struct kvm_rmap_head parent_ptes; /* rmap pointers to parent sptes */
DECLARE_BITMAP(unsync_child_bitmap, 512);
struct list_head lpage_disallowed_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 struct kvm_mmu_page *to_shadow_page(hpa_t shadow_page)
{
struct page *page = pfn_to_page(shadow_page >> PAGE_SHIFT);
return (struct kvm_mmu_page *)page_private(page);
}
static inline struct kvm_mmu_page *sptep_to_sp(u64 *sptep)
{
return to_shadow_page(__pa(sptep));
}
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;
}
int mmu_try_to_unsync_pages(struct kvm_vcpu *vcpu, 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_with_address(struct kvm *kvm,
u64 start_gfn, u64 pages);
unsigned int pte_list_count(struct kvm_rmap_head *rmap_head);
/*
* Return values of handle_mmio_page_fault, mmu.page_fault, and fast_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
*/
enum {
RET_PF_RETRY = 0,
RET_PF_EMULATE,
RET_PF_INVALID,
RET_PF_FIXED,
RET_PF_SPURIOUS,
};
int kvm_mmu_max_mapping_level(struct kvm *kvm,
const struct kvm_memory_slot *slot, gfn_t gfn,
kvm_pfn_t pfn, 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 account_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp);
void unaccount_huge_nx_page(struct kvm *kvm, struct kvm_mmu_page *sp);
#endif /* __KVM_X86_MMU_INTERNAL_H */