[PATCH 4.14 096/110] KVM: x86: extend usage of RET_MMIO_PF_* constants

4.14-stable review patch. If anyone has any objections, please let me know.

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From: Paolo Bonzini pbonzini@redhat.com

commit 9b8ebbdb74b5ad76b9dfd8b101af17839174b126 upstream.

The x86 MMU if full of code that returns 0 and 1 for retry/emulate. Use the existing RET_MMIO_PF_RETRY/RET_MMIO_PF_EMULATE enum, renaming it to drop the MMIO part.

Signed-off-by: Paolo Bonzini pbonzini@redhat.com Cc: Thomas Backlund tmb@mageia.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- arch/x86/kvm/mmu.c | 95 +++++++++++++++++++++------------------------ arch/x86/kvm/paging_tmpl.h | 18 ++++---- 2 files changed, 55 insertions(+), 58 deletions(-)

--- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -150,6 +150,20 @@ module_param(dbg, bool, 0644); /* make pte_list_desc fit well in cache line */ #define PTE_LIST_EXT 3

+/* + * Return values of handle_mmio_page_fault and mmu.page_fault: + * RET_PF_RETRY: let CPU fault again on the address. + * RET_PF_EMULATE: mmio page fault, emulate the instruction directly. + * + * For handle_mmio_page_fault only: + * RET_PF_INVALID: the spte is invalid, let the real page fault path update it. + */ +enum { + RET_PF_RETRY = 0, + RET_PF_EMULATE = 1, + RET_PF_INVALID = 2, +}; + struct pte_list_desc { u64 *sptes[PTE_LIST_EXT]; struct pte_list_desc *more; @@ -2794,13 +2808,13 @@ done: return ret; }

-static bool mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access, - int write_fault, int level, gfn_t gfn, kvm_pfn_t pfn, - bool speculative, bool host_writable) +static int mmu_set_spte(struct kvm_vcpu *vcpu, u64 *sptep, unsigned pte_access, + int write_fault, int level, gfn_t gfn, kvm_pfn_t pfn, + bool speculative, bool host_writable) { int was_rmapped = 0; int rmap_count; - bool emulate = false; + int ret = RET_PF_RETRY;

pgprintk("%s: spte %llx write_fault %d gfn %llx\n", __func__, *sptep, write_fault, gfn); @@ -2830,12 +2844,12 @@ static bool mmu_set_spte(struct kvm_vcpu if (set_spte(vcpu, sptep, pte_access, level, gfn, pfn, speculative, true, host_writable)) { if (write_fault) - emulate = true; + ret = RET_PF_EMULATE; kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu); }

if (unlikely(is_mmio_spte(*sptep))) - emulate = true; + ret = RET_PF_EMULATE;

pgprintk("%s: setting spte %llx\n", __func__, *sptep); pgprintk("instantiating %s PTE (%s) at %llx (%llx) addr %p\n", @@ -2855,7 +2869,7 @@ static bool mmu_set_spte(struct kvm_vcpu

kvm_release_pfn_clean(pfn);

- return emulate; + return ret; }

static kvm_pfn_t pte_prefetch_gfn_to_pfn(struct kvm_vcpu *vcpu, gfn_t gfn, @@ -2994,14 +3008,13 @@ static int kvm_handle_bad_page(struct kv * Do not cache the mmio info caused by writing the readonly gfn * into the spte otherwise read access on readonly gfn also can * caused mmio page fault and treat it as mmio access. - * Return 1 to tell kvm to emulate it. */ if (pfn == KVM_PFN_ERR_RO_FAULT) - return 1; + return RET_PF_EMULATE;

if (pfn == KVM_PFN_ERR_HWPOISON) { kvm_send_hwpoison_signal(kvm_vcpu_gfn_to_hva(vcpu, gfn), current); - return 0; + return RET_PF_RETRY; }

return -EFAULT; @@ -3286,13 +3299,13 @@ static int nonpaging_map(struct kvm_vcpu }

if (fast_page_fault(vcpu, v, level, error_code)) - return 0; + return RET_PF_RETRY;

mmu_seq = vcpu->kvm->mmu_notifier_seq; smp_rmb();

if (try_async_pf(vcpu, prefault, gfn, v, &pfn, write, &map_writable)) - return 0; + return RET_PF_RETRY;

if (handle_abnormal_pfn(vcpu, v, gfn, pfn, ACC_ALL, &r)) return r; @@ -3312,7 +3325,7 @@ static int nonpaging_map(struct kvm_vcpu out_unlock: spin_unlock(&vcpu->kvm->mmu_lock); kvm_release_pfn_clean(pfn); - return 0; + return RET_PF_RETRY; }

@@ -3659,54 +3672,38 @@ exit: return reserved; }

-/* - * Return values of handle_mmio_page_fault: - * RET_MMIO_PF_EMULATE: it is a real mmio page fault, emulate the instruction - * directly. - * RET_MMIO_PF_INVALID: invalid spte is detected then let the real page - * fault path update the mmio spte. - * RET_MMIO_PF_RETRY: let CPU fault again on the address. - * RET_MMIO_PF_BUG: a bug was detected (and a WARN was printed). - */ -enum { - RET_MMIO_PF_EMULATE = 1, - RET_MMIO_PF_INVALID = 2, - RET_MMIO_PF_RETRY = 0, - RET_MMIO_PF_BUG = -1 -}; - static int handle_mmio_page_fault(struct kvm_vcpu *vcpu, u64 addr, bool direct) { u64 spte; bool reserved;

if (mmio_info_in_cache(vcpu, addr, direct)) - return RET_MMIO_PF_EMULATE; + return RET_PF_EMULATE;

reserved = walk_shadow_page_get_mmio_spte(vcpu, addr, &spte); if (WARN_ON(reserved)) - return RET_MMIO_PF_BUG; + return -EINVAL;

if (is_mmio_spte(spte)) { gfn_t gfn = get_mmio_spte_gfn(spte); unsigned access = get_mmio_spte_access(spte);

if (!check_mmio_spte(vcpu, spte)) - return RET_MMIO_PF_INVALID; + return RET_PF_INVALID;

if (direct) addr = 0;

trace_handle_mmio_page_fault(addr, gfn, access); vcpu_cache_mmio_info(vcpu, addr, gfn, access); - return RET_MMIO_PF_EMULATE; + return RET_PF_EMULATE; }

/* * If the page table is zapped by other cpus, let CPU fault again on * the address. */ - return RET_MMIO_PF_RETRY; + return RET_PF_RETRY; } EXPORT_SYMBOL_GPL(handle_mmio_page_fault);

@@ -3756,7 +3753,7 @@ static int nonpaging_page_fault(struct k pgprintk("%s: gva %lx error %x\n", __func__, gva, error_code);

if (page_fault_handle_page_track(vcpu, error_code, gfn)) - return 1; + return RET_PF_EMULATE;

r = mmu_topup_memory_caches(vcpu); if (r) @@ -3877,7 +3874,7 @@ static int tdp_page_fault(struct kvm_vcp MMU_WARN_ON(!VALID_PAGE(vcpu->arch.mmu.root_hpa));

if (page_fault_handle_page_track(vcpu, error_code, gfn)) - return 1; + return RET_PF_EMULATE;

r = mmu_topup_memory_caches(vcpu); if (r) @@ -3894,13 +3891,13 @@ static int tdp_page_fault(struct kvm_vcp }

if (fast_page_fault(vcpu, gpa, level, error_code)) - return 0; + return RET_PF_RETRY;

mmu_seq = vcpu->kvm->mmu_notifier_seq; smp_rmb();

if (try_async_pf(vcpu, prefault, gfn, gpa, &pfn, write, &map_writable)) - return 0; + return RET_PF_RETRY;

if (handle_abnormal_pfn(vcpu, 0, gfn, pfn, ACC_ALL, &r)) return r; @@ -3920,7 +3917,7 @@ static int tdp_page_fault(struct kvm_vcp out_unlock: spin_unlock(&vcpu->kvm->mmu_lock); kvm_release_pfn_clean(pfn); - return 0; + return RET_PF_RETRY; }

static void nonpaging_init_context(struct kvm_vcpu *vcpu, @@ -4919,25 +4916,25 @@ int kvm_mmu_page_fault(struct kvm_vcpu * vcpu->arch.gpa_val = cr2; }

+ r = RET_PF_INVALID; if (unlikely(error_code & PFERR_RSVD_MASK)) { r = handle_mmio_page_fault(vcpu, cr2, direct); - if (r == RET_MMIO_PF_EMULATE) { + if (r == RET_PF_EMULATE) { emulation_type = 0; goto emulate; } - if (r == RET_MMIO_PF_RETRY) - return 1; - if (r < 0) - return r; - /* Must be RET_MMIO_PF_INVALID. */ }

- r = vcpu->arch.mmu.page_fault(vcpu, cr2, lower_32_bits(error_code), - false); + if (r == RET_PF_INVALID) { + r = vcpu->arch.mmu.page_fault(vcpu, cr2, lower_32_bits(error_code), + false); + WARN_ON(r == RET_PF_INVALID); + } + + if (r == RET_PF_RETRY) + return 1; if (r < 0) return r; - if (!r) - return 1;

/* * Before emulating the instruction, check if the error code --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -593,7 +593,7 @@ static int FNAME(fetch)(struct kvm_vcpu struct kvm_mmu_page *sp = NULL; struct kvm_shadow_walk_iterator it; unsigned direct_access, access = gw->pt_access; - int top_level, emulate; + int top_level, ret;

direct_access = gw->pte_access;

@@ -659,15 +659,15 @@ static int FNAME(fetch)(struct kvm_vcpu }

clear_sp_write_flooding_count(it.sptep); - emulate = mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault, - it.level, gw->gfn, pfn, prefault, map_writable); + ret = mmu_set_spte(vcpu, it.sptep, gw->pte_access, write_fault, + it.level, gw->gfn, pfn, prefault, map_writable); FNAME(pte_prefetch)(vcpu, gw, it.sptep);

- return emulate; + return ret;

out_gpte_changed: kvm_release_pfn_clean(pfn); - return 0; + return RET_PF_RETRY; }

/* @@ -762,12 +762,12 @@ static int FNAME(page_fault)(struct kvm_ if (!prefault) inject_page_fault(vcpu, &walker.fault);

- return 0; + return RET_PF_RETRY; }

if (page_fault_handle_page_track(vcpu, error_code, walker.gfn)) { shadow_page_table_clear_flood(vcpu, addr); - return 1; + return RET_PF_EMULATE; }

vcpu->arch.write_fault_to_shadow_pgtable = false; @@ -789,7 +789,7 @@ static int FNAME(page_fault)(struct kvm_

if (try_async_pf(vcpu, prefault, walker.gfn, addr, &pfn, write_fault, &map_writable)) - return 0; + return RET_PF_RETRY;

if (handle_abnormal_pfn(vcpu, addr, walker.gfn, pfn, walker.pte_access, &r)) return r; @@ -834,7 +834,7 @@ static int FNAME(page_fault)(struct kvm_ out_unlock: spin_unlock(&vcpu->kvm->mmu_lock); kvm_release_pfn_clean(pfn); - return 0; + return RET_PF_RETRY; }

static gpa_t FNAME(get_level1_sp_gpa)(struct kvm_mmu_page *sp)