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authorPaolo Bonzini <pbonzini@redhat.com>2024-05-12 10:18:44 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2024-05-12 10:18:44 +0300
commit7d41e24da29a83acc52a78a68aa515dd76e41cc1 (patch)
tree4ab35b9e1c69ff5b454844a0df16ee483ffc1f2d
parent5a1c72e07e830dda424f2929332a1435c9736da3 (diff)
parent51937f2aae186e335175dde78279aaf0cb5e72ae (diff)
downloadlinux-7d41e24da29a83acc52a78a68aa515dd76e41cc1.tar.xz
Merge tag 'kvm-x86-misc-6.10' of https://github.com/kvm-x86/linux into HEAD
KVM x86 misc changes for 6.10: - Advertise the max mappable GPA in the "guest MAXPHYADDR" CPUID field, which is unused by hardware, so that KVM can communicate its inability to map GPAs that set bits 51:48 due to lack of 5-level paging. Guest firmware is expected to use the information to safely remap BARs in the uppermost GPA space, i.e to avoid placing a BAR at a legal, but unmappable, GPA. - Use vfree() instead of kvfree() for allocations that always use vcalloc() or __vcalloc(). - Don't completely ignore same-value writes to immutable feature MSRs, as doing so results in KVM failing to reject accesses to MSR that aren't supposed to exist given the vCPU model and/or KVM configuration. - Don't mark APICv as being inhibited due to ABSENT if APICv is disabled KVM-wide to avoid confusing debuggers (KVM will never bother clearing the ABSENT inhibit, even if userspace enables in-kernel local APIC).
-rw-r--r--arch/x86/kvm/cpuid.c41
-rw-r--r--arch/x86/kvm/mmu.h2
-rw-r--r--arch/x86/kvm/mmu/mmu.c5
-rw-r--r--arch/x86/kvm/mmu/page_track.c2
-rw-r--r--arch/x86/kvm/trace.h4
-rw-r--r--arch/x86/kvm/x86.c28
-rw-r--r--virt/kvm/kvm_main.c2
7 files changed, 53 insertions, 31 deletions
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 1851b3870a9c..f2f2be5d1141 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -1232,9 +1232,22 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
entry->eax = entry->ebx = entry->ecx = 0;
break;
case 0x80000008: {
- unsigned g_phys_as = (entry->eax >> 16) & 0xff;
- unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
- unsigned phys_as = entry->eax & 0xff;
+ /*
+ * GuestPhysAddrSize (EAX[23:16]) is intended for software
+ * use.
+ *
+ * KVM's ABI is to report the effective MAXPHYADDR for the
+ * guest in PhysAddrSize (phys_as), and the maximum
+ * *addressable* GPA in GuestPhysAddrSize (g_phys_as).
+ *
+ * GuestPhysAddrSize is valid if and only if TDP is enabled,
+ * in which case the max GPA that can be addressed by KVM may
+ * be less than the max GPA that can be legally generated by
+ * the guest, e.g. if MAXPHYADDR>48 but the CPU doesn't
+ * support 5-level TDP.
+ */
+ unsigned int virt_as = max((entry->eax >> 8) & 0xff, 48U);
+ unsigned int phys_as, g_phys_as;
/*
* If TDP (NPT) is disabled use the adjusted host MAXPHYADDR as
@@ -1242,16 +1255,24 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
* reductions in MAXPHYADDR for memory encryption affect shadow
* paging, too.
*
- * If TDP is enabled but an explicit guest MAXPHYADDR is not
- * provided, use the raw bare metal MAXPHYADDR as reductions to
- * the HPAs do not affect GPAs.
+ * If TDP is enabled, use the raw bare metal MAXPHYADDR as
+ * reductions to the HPAs do not affect GPAs. The max
+ * addressable GPA is the same as the max effective GPA, except
+ * that it's capped at 48 bits if 5-level TDP isn't supported
+ * (hardware processes bits 51:48 only when walking the fifth
+ * level page table).
*/
- if (!tdp_enabled)
- g_phys_as = boot_cpu_data.x86_phys_bits;
- else if (!g_phys_as)
+ if (!tdp_enabled) {
+ phys_as = boot_cpu_data.x86_phys_bits;
+ g_phys_as = 0;
+ } else {
+ phys_as = entry->eax & 0xff;
g_phys_as = phys_as;
+ if (kvm_mmu_get_max_tdp_level() < 5)
+ g_phys_as = min(g_phys_as, 48);
+ }
- entry->eax = g_phys_as | (virt_as << 8);
+ entry->eax = phys_as | (virt_as << 8) | (g_phys_as << 16);
entry->ecx &= ~(GENMASK(31, 16) | GENMASK(11, 8));
entry->edx = 0;
cpuid_entry_override(entry, CPUID_8000_0008_EBX);
diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index 2343c9f00e31..2e454316f2a2 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -100,6 +100,8 @@ static inline u8 kvm_get_shadow_phys_bits(void)
return boot_cpu_data.x86_phys_bits;
}
+u8 kvm_mmu_get_max_tdp_level(void);
+
void kvm_mmu_set_mmio_spte_mask(u64 mmio_value, u64 mmio_mask, u64 access_mask);
void kvm_mmu_set_me_spte_mask(u64 me_value, u64 me_mask);
void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only);
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 99f7b2f3d82a..662f62dfb2aa 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5316,6 +5316,11 @@ static inline int kvm_mmu_get_tdp_level(struct kvm_vcpu *vcpu)
return max_tdp_level;
}
+u8 kvm_mmu_get_max_tdp_level(void)
+{
+ return tdp_root_level ? tdp_root_level : max_tdp_level;
+}
+
static union kvm_mmu_page_role
kvm_calc_tdp_mmu_root_page_role(struct kvm_vcpu *vcpu,
union kvm_cpu_role cpu_role)
diff --git a/arch/x86/kvm/mmu/page_track.c b/arch/x86/kvm/mmu/page_track.c
index f6448284c18e..561c331fd6ec 100644
--- a/arch/x86/kvm/mmu/page_track.c
+++ b/arch/x86/kvm/mmu/page_track.c
@@ -41,7 +41,7 @@ bool kvm_page_track_write_tracking_enabled(struct kvm *kvm)
void kvm_page_track_free_memslot(struct kvm_memory_slot *slot)
{
- kvfree(slot->arch.gfn_write_track);
+ vfree(slot->arch.gfn_write_track);
slot->arch.gfn_write_track = NULL;
}
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index c6b4b1728006..9d0b02ef307e 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -1074,7 +1074,7 @@ TRACE_EVENT(kvm_smm_transition,
);
/*
- * Tracepoint for VT-d posted-interrupts.
+ * Tracepoint for VT-d posted-interrupts and AMD-Vi Guest Virtual APIC.
*/
TRACE_EVENT(kvm_pi_irte_update,
TP_PROTO(unsigned int host_irq, unsigned int vcpu_id,
@@ -1100,7 +1100,7 @@ TRACE_EVENT(kvm_pi_irte_update,
__entry->set = set;
),
- TP_printk("VT-d PI is %s for irq %u, vcpu %u, gsi: 0x%x, "
+ TP_printk("PI is %s for irq %u, vcpu %u, gsi: 0x%x, "
"gvec: 0x%x, pi_desc_addr: 0x%llx",
__entry->set ? "enabled and being updated" : "disabled",
__entry->host_irq,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fda22b3800a1..082ac6d95a3a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2233,16 +2233,13 @@ static int do_set_msr(struct kvm_vcpu *vcpu, unsigned index, u64 *data)
/*
* Disallow writes to immutable feature MSRs after KVM_RUN. KVM does
* not support modifying the guest vCPU model on the fly, e.g. changing
- * the nVMX capabilities while L2 is running is nonsensical. Ignore
+ * the nVMX capabilities while L2 is running is nonsensical. Allow
* writes of the same value, e.g. to allow userspace to blindly stuff
* all MSRs when emulating RESET.
*/
- if (kvm_vcpu_has_run(vcpu) && kvm_is_immutable_feature_msr(index)) {
- if (do_get_msr(vcpu, index, &val) || *data != val)
- return -EINVAL;
-
- return 0;
- }
+ if (kvm_vcpu_has_run(vcpu) && kvm_is_immutable_feature_msr(index) &&
+ (do_get_msr(vcpu, index, &val) || *data != val))
+ return -EINVAL;
return kvm_set_msr_ignored_check(vcpu, index, *data, true);
}
@@ -10031,15 +10028,12 @@ static void set_or_clear_apicv_inhibit(unsigned long *inhibits,
static void kvm_apicv_init(struct kvm *kvm)
{
- unsigned long *inhibits = &kvm->arch.apicv_inhibit_reasons;
+ enum kvm_apicv_inhibit reason = enable_apicv ? APICV_INHIBIT_REASON_ABSENT :
+ APICV_INHIBIT_REASON_DISABLE;
- init_rwsem(&kvm->arch.apicv_update_lock);
-
- set_or_clear_apicv_inhibit(inhibits, APICV_INHIBIT_REASON_ABSENT, true);
+ set_or_clear_apicv_inhibit(&kvm->arch.apicv_inhibit_reasons, reason, true);
- if (!enable_apicv)
- set_or_clear_apicv_inhibit(inhibits,
- APICV_INHIBIT_REASON_DISABLE, true);
+ init_rwsem(&kvm->arch.apicv_update_lock);
}
static void kvm_sched_yield(struct kvm_vcpu *vcpu, unsigned long dest_id)
@@ -12805,7 +12799,7 @@ static void memslot_rmap_free(struct kvm_memory_slot *slot)
int i;
for (i = 0; i < KVM_NR_PAGE_SIZES; ++i) {
- kvfree(slot->arch.rmap[i]);
+ vfree(slot->arch.rmap[i]);
slot->arch.rmap[i] = NULL;
}
}
@@ -12817,7 +12811,7 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *slot)
memslot_rmap_free(slot);
for (i = 1; i < KVM_NR_PAGE_SIZES; ++i) {
- kvfree(slot->arch.lpage_info[i - 1]);
+ vfree(slot->arch.lpage_info[i - 1]);
slot->arch.lpage_info[i - 1] = NULL;
}
@@ -12909,7 +12903,7 @@ out_free:
memslot_rmap_free(slot);
for (i = 1; i < KVM_NR_PAGE_SIZES; ++i) {
- kvfree(slot->arch.lpage_info[i - 1]);
+ vfree(slot->arch.lpage_info[i - 1]);
slot->arch.lpage_info[i - 1] = NULL;
}
return -ENOMEM;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index fb86ec20ebc4..a1756d5077ee 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -974,7 +974,7 @@ static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
if (!memslot->dirty_bitmap)
return;
- kvfree(memslot->dirty_bitmap);
+ vfree(memslot->dirty_bitmap);
memslot->dirty_bitmap = NULL;
}