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Message-Id: <1e5ce007ad1046ee34408708c0e369b7fcab917b.1605232743.git.isaku.yamahata@intel.com>
Date: Mon, 16 Nov 2020 10:26:21 -0800
From: isaku.yamahata@...el.com
To: Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
"H . Peter Anvin" <hpa@...or.com>,
Paolo Bonzini <pbonzini@...hat.com>,
Vitaly Kuznetsov <vkuznets@...hat.com>,
Wanpeng Li <wanpengli@...cent.com>,
Jim Mattson <jmattson@...gle.com>,
Joerg Roedel <joro@...tes.org>, x86@...nel.org,
linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc: isaku.yamahata@...el.com, isaku.yamahata@...il.com,
Sean Christopherson <sean.j.christopherson@...el.com>
Subject: [RFC PATCH 36/67] KVM: x86/mmu: Track shadow MMIO value on a per-VM basis
From: Sean Christopherson <sean.j.christopherson@...el.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@...el.com>
---
arch/x86/include/asm/kvm_host.h | 2 ++
arch/x86/kvm/mmu.h | 4 +++-
arch/x86/kvm/mmu/mmu.c | 24 +++---------------------
arch/x86/kvm/mmu/spte.c | 26 ++++++++++++++++++++++----
arch/x86/kvm/mmu/spte.h | 2 +-
arch/x86/kvm/svm/svm.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 18 +++++++-----------
7 files changed, 39 insertions(+), 39 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 6dfc09092bc9..d4fd9859fcd5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -915,6 +915,8 @@ struct kvm_arch {
struct kvm_page_track_notifier_node mmu_sp_tracker;
struct kvm_page_track_notifier_head track_notifier_head;
+ u64 shadow_mmio_value;
+
struct list_head assigned_dev_head;
struct iommu_domain *iommu_domain;
bool iommu_noncoherent;
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 7ce8f0256d6d..05c2898cb2a2 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -52,7 +52,9 @@ static inline u64 rsvd_bits(int s, int e)
return ((1ULL << (e - s + 1)) - 1) << s;
}
-void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 access_mask);
+void kvm_mmu_set_mmio_spte_mask(struct kvm *kvm, u64 mmio_value,
+ u64 access_mask);
+void kvm_mmu_set_default_mmio_spte_mask(u64 mask);
void
reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index c4d657b26066..da2a58fa86a8 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5507,6 +5507,9 @@ void kvm_mmu_init_vm(struct kvm *kvm)
node->track_write = kvm_mmu_pte_write;
node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot;
kvm_page_track_register_notifier(kvm, node);
+
+ kvm_mmu_set_mmio_spte_mask(kvm, shadow_default_mmio_mask,
+ ACC_WRITE_MASK | ACC_USER_MASK);
}
void kvm_mmu_uninit_vm(struct kvm *kvm)
@@ -5835,25 +5838,6 @@ static void mmu_destroy_caches(void)
kmem_cache_destroy(mmu_page_header_cache);
}
-static void kvm_set_mmio_spte_mask(void)
-{
- u64 mask;
-
- /*
- * Set a reserved PA bit in MMIO SPTEs to generate page faults with
- * PFEC.RSVD=1 on MMIO accesses. 64-bit PTEs (PAE, x86-64, and EPT
- * paging) support a maximum of 52 bits of PA, i.e. if the CPU supports
- * 52-bit physical addresses then there are no reserved PA bits in the
- * PTEs and so the reserved PA approach must be disabled.
- */
- if (shadow_phys_bits < 52)
- mask = BIT_ULL(51) | PT_PRESENT_MASK;
- else
- mask = 0;
-
- kvm_mmu_set_mmio_spte_mask(mask, ACC_WRITE_MASK | ACC_USER_MASK);
-}
-
static bool get_nx_auto_mode(void)
{
/* Return true when CPU has the bug, and mitigations are ON */
@@ -5919,8 +5903,6 @@ int kvm_mmu_module_init(void)
kvm_mmu_reset_all_pte_masks();
- kvm_set_mmio_spte_mask();
-
pte_list_desc_cache = kmem_cache_create("pte_list_desc",
sizeof(struct pte_list_desc),
0, SLAB_ACCOUNT, NULL);
diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c
index fcac2cac78fe..574c8ccac0bf 100644
--- a/arch/x86/kvm/mmu/spte.c
+++ b/arch/x86/kvm/mmu/spte.c
@@ -22,7 +22,7 @@ u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
u64 __read_mostly shadow_user_mask;
u64 __read_mostly shadow_accessed_mask;
u64 __read_mostly shadow_dirty_mask;
-u64 __read_mostly shadow_mmio_value;
+u64 __read_mostly shadow_default_mmio_mask;
u64 __read_mostly shadow_mmio_access_mask;
u64 __read_mostly shadow_present_mask;
u64 __read_mostly shadow_me_mask;
@@ -52,7 +52,7 @@ u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access)
u64 gpa = gfn << PAGE_SHIFT;
access &= shadow_mmio_access_mask;
- mask |= shadow_mmio_value | access;
+ mask |= vcpu->kvm->arch.shadow_mmio_value | SPTE_MMIO_MASK | access;
mask |= gpa | shadow_nonpresent_or_rsvd_mask;
mask |= (gpa & shadow_nonpresent_or_rsvd_mask)
<< SHADOW_NONPRESENT_OR_RSVD_MASK_LEN;
@@ -242,12 +242,13 @@ u64 mark_spte_for_access_track(u64 spte)
return spte;
}
-void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 access_mask)
+void kvm_mmu_set_mmio_spte_mask(struct kvm *kvm, u64 mmio_value,
+ u64 access_mask)
{
BUG_ON((u64)(unsigned)access_mask != access_mask);
WARN_ON(mmio_value & (shadow_nonpresent_or_rsvd_mask << SHADOW_NONPRESENT_OR_RSVD_MASK_LEN));
WARN_ON(mmio_value & shadow_nonpresent_or_rsvd_lower_gfn_mask);
- shadow_mmio_value = mmio_value | SPTE_MMIO_MASK;
+ kvm->arch.shadow_mmio_value = mmio_value | SPTE_MMIO_MASK;
shadow_mmio_access_mask = access_mask;
}
EXPORT_SYMBOL_GPL(kvm_mmu_set_mmio_spte_mask);
@@ -289,6 +290,7 @@ void kvm_mmu_reset_all_pte_masks(void)
shadow_x_mask = 0;
shadow_present_mask = 0;
shadow_acc_track_mask = 0;
+ shadow_default_mmio_mask = 0;
shadow_phys_bits = kvm_get_shadow_phys_bits();
@@ -315,4 +317,20 @@ void kvm_mmu_reset_all_pte_masks(void)
shadow_nonpresent_or_rsvd_lower_gfn_mask =
GENMASK_ULL(low_phys_bits - 1, PAGE_SHIFT);
+
+ /*
+ * Set a reserved PA bit in MMIO SPTEs to generate page faults with
+ * PFEC.RSVD=1 on MMIO accesses. 64-bit PTEs (PAE, x86-64, and EPT
+ * paging) support a maximum of 52 bits of PA, i.e. if the CPU supports
+ * 52-bit physical addresses then there are no reserved PA bits in the
+ * PTEs and so the reserved PA approach must be disabled.
+ */
+ if (shadow_phys_bits < 52)
+ shadow_default_mmio_mask = BIT_ULL(51) | PT_PRESENT_MASK;
+}
+
+void kvm_mmu_set_default_mmio_spte_mask(u64 mask)
+{
+ shadow_default_mmio_mask = mask;
}
+EXPORT_SYMBOL_GPL(kvm_mmu_set_default_mmio_spte_mask);
diff --git a/arch/x86/kvm/mmu/spte.h b/arch/x86/kvm/mmu/spte.h
index 5c75a451c000..e5c94848ade1 100644
--- a/arch/x86/kvm/mmu/spte.h
+++ b/arch/x86/kvm/mmu/spte.h
@@ -86,7 +86,7 @@ extern u64 __read_mostly shadow_x_mask; /* mutual exclusive with nx_mask */
extern u64 __read_mostly shadow_user_mask;
extern u64 __read_mostly shadow_accessed_mask;
extern u64 __read_mostly shadow_dirty_mask;
-extern u64 __read_mostly shadow_mmio_value;
+extern u64 __read_mostly shadow_default_mmio_mask;
extern u64 __read_mostly shadow_mmio_access_mask;
extern u64 __read_mostly shadow_present_mask;
extern u64 __read_mostly shadow_me_mask;
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 8be23240c74f..0aa29a30f922 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -871,7 +871,7 @@ static __init void svm_adjust_mmio_mask(void)
*/
mask = (mask_bit < 52) ? rsvd_bits(mask_bit, 51) | PT_PRESENT_MASK : 0;
- kvm_mmu_set_mmio_spte_mask(mask, PT_WRITABLE_MASK | PT_USER_MASK);
+ kvm_mmu_set_default_mmio_spte_mask(mask);
}
static void svm_hardware_teardown(void)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index deeec105e963..997a391f0842 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4276,15 +4276,6 @@ static void vmx_compute_secondary_exec_control(struct vcpu_vmx *vmx)
vmx->secondary_exec_control = exec_control;
}
-static void ept_set_mmio_spte_mask(void)
-{
- /*
- * EPT Misconfigurations can be generated if the value of bits 2:0
- * of an EPT paging-structure entry is 110b (write/execute).
- */
- kvm_mmu_set_mmio_spte_mask(VMX_EPT_MISCONFIG_WX_VALUE, 0);
-}
-
#define VMX_XSS_EXIT_BITMAP 0
/*
@@ -5473,8 +5464,6 @@ static void vmx_enable_tdp(void)
0ull, VMX_EPT_EXECUTABLE_MASK,
cpu_has_vmx_ept_execute_only() ? 0ull : VMX_EPT_READABLE_MASK,
VMX_EPT_RWX_MASK, 0ull);
-
- ept_set_mmio_spte_mask();
}
/*
@@ -6983,6 +6972,13 @@ static int vmx_vm_init(struct kvm *kvm)
if (!ple_gap)
kvm->arch.pause_in_guest = true;
+ /*
+ * EPT Misconfigurations can be generated if the value of bits 2:0
+ * of an EPT paging-structure entry is 110b (write/execute).
+ */
+ if (enable_ept)
+ kvm_mmu_set_mmio_spte_mask(kvm, VMX_EPT_MISCONFIG_WX_VALUE, 0);
+
if (boot_cpu_has(X86_BUG_L1TF) && enable_ept) {
switch (l1tf_mitigation) {
case L1TF_MITIGATION_OFF:
--
2.17.1
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