lkml.org 
[lkml]   [2022]   [Dec]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH RFC v7 04/64] KVM: x86: Add 'fault_is_private' x86 op
Date
This callback is used by the KVM MMU to check whether a #NPF was
or a private GPA or not.

Signed-off-by: Michael Roth <michael.roth@amd.com>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 +
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/mmu/mmu.c | 3 +--
arch/x86/kvm/mmu/mmu_internal.h | 40 +++++++++++++++++++++++++++---
4 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index f530a550c092..efae987cdce0 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -132,6 +132,7 @@ KVM_X86_OP(complete_emulated_msr)
KVM_X86_OP(vcpu_deliver_sipi_vector)
KVM_X86_OP_OPTIONAL_RET0(vcpu_get_apicv_inhibit_reasons);
KVM_X86_OP_OPTIONAL_RET0(private_mem_enabled);
+KVM_X86_OP_OPTIONAL_RET0(fault_is_private);

#undef KVM_X86_OP
#undef KVM_X86_OP_OPTIONAL
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9317abffbf68..92539708f062 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1636,6 +1636,7 @@ struct kvm_x86_ops {
void (*load_mmu_pgd)(struct kvm_vcpu *vcpu, hpa_t root_hpa,
int root_level);
int (*private_mem_enabled)(struct kvm *kvm);
+ int (*fault_is_private)(struct kvm *kvm, gpa_t gpa, u64 error_code, bool *private_fault);

bool (*has_wbinvd_exit)(void);

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index b3ffc61c668c..61a7c221b966 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5646,8 +5646,7 @@ int noinline kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 err
}

if (r == RET_PF_INVALID) {
- r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa,
- lower_32_bits(error_code), false);
+ r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa, error_code, false);
if (KVM_BUG_ON(r == RET_PF_INVALID, vcpu->kvm))
return -EIO;
}
diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h
index e2f508db0b6e..04ea8da86510 100644
--- a/arch/x86/kvm/mmu/mmu_internal.h
+++ b/arch/x86/kvm/mmu/mmu_internal.h
@@ -230,6 +230,38 @@ struct kvm_page_fault {

int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault);

+static bool kvm_mmu_fault_is_private(struct kvm *kvm, gpa_t gpa, u64 err)
+{
+ struct kvm_memory_slot *slot;
+ bool private_fault = false;
+ gfn_t gfn = gpa_to_gfn(gpa);
+
+ slot = gfn_to_memslot(kvm, gfn);
+ if (!slot) {
+ pr_debug("%s: no slot, GFN: 0x%llx\n", __func__, gfn);
+ goto out;
+ }
+
+ if (!kvm_slot_can_be_private(slot)) {
+ pr_debug("%s: slot is not private, GFN: 0x%llx\n", __func__, gfn);
+ goto out;
+ }
+
+ if (static_call(kvm_x86_fault_is_private)(kvm, gpa, err, &private_fault) == 1)
+ goto out;
+
+ /*
+ * Handling below is for UPM self-tests and guests that use
+ * slot->shared_bitmap for encrypted access tracking.
+ */
+ if (IS_ENABLED(CONFIG_HAVE_KVM_PRIVATE_MEM_TESTING))
+ private_fault = kvm_mem_is_private(kvm, gpa >> PAGE_SHIFT);
+
+out:
+ pr_debug("%s: GFN: 0x%llx, private: %d\n", __func__, gfn, private_fault);
+ return private_fault;
+}
+
/*
* Return values of handle_mmio_page_fault(), mmu.page_fault(), fast_page_fault(),
* and of course kvm_mmu_do_page_fault().
@@ -261,13 +293,13 @@ enum {
};

static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
- u32 err, bool prefetch)
+ u64 err, bool prefetch)
{
bool is_tdp = likely(vcpu->arch.mmu->page_fault == kvm_tdp_page_fault);

struct kvm_page_fault fault = {
.addr = cr2_or_gpa,
- .error_code = err,
+ .error_code = lower_32_bits(err),
.exec = err & PFERR_FETCH_MASK,
.write = err & PFERR_WRITE_MASK,
.present = err & PFERR_PRESENT_MASK,
@@ -281,8 +313,8 @@ static inline int kvm_mmu_do_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
.max_level = KVM_MAX_HUGEPAGE_LEVEL,
.req_level = PG_LEVEL_4K,
.goal_level = PG_LEVEL_4K,
- .is_private = IS_ENABLED(CONFIG_HAVE_KVM_PRIVATE_MEM_TESTING) && is_tdp &&
- kvm_mem_is_private(vcpu->kvm, cr2_or_gpa >> PAGE_SHIFT),
+ .is_private = is_tdp && kvm_mmu_fault_is_private(vcpu->kvm,
+ cr2_or_gpa, err),
};
int r;

--
2.25.1
\
 
 \ /
  Last update: 2022-12-14 21:12    [W:1.913 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site