[tip:x86/mm] kvm/x86/svm: Support Secure Memory Encryption within KVM

From: tip-bot for Tom Lendacky
Date: Tue Jul 18 2017 - 07:06:30 EST

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Commit-ID: d0ec49d4de90806755e17289bd48464a1a515823
Gitweb: http://git.kernel.org/tip/d0ec49d4de90806755e17289bd48464a1a515823
Author: Tom Lendacky <thomas.lendacky@xxxxxxx>
AuthorDate: Mon, 17 Jul 2017 16:10:27 -0500
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 18 Jul 2017 11:38:04 +0200

kvm/x86/svm: Support Secure Memory Encryption within KVM

Update the KVM support to work with SME. The VMCB has a number of fields
where physical addresses are used and these addresses must contain the
memory encryption mask in order to properly access the encrypted memory.
Also, use the memory encryption mask when creating and using the nested
page tables.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Reviewed-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brijesh Singh <brijesh.singh@xxxxxxx>
Cc: Dave Young <dyoung@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Larry Woodman <lwoodman@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Michael S. Tsirkin <mst@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Toshimitsu Kani <toshi.kani@xxxxxxx>
Cc: kasan-dev@xxxxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-arch@xxxxxxxxxxxxxxx
Cc: linux-doc@xxxxxxxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Link: http://lkml.kernel.org/r/89146eccfa50334409801ff20acd52a90fb5efcf.1500319216.git.thomas.lendacky@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/mmu.c | 11 +++++++----
arch/x86/kvm/mmu.h | 2 +-
arch/x86/kvm/svm.c | 35 ++++++++++++++++++-----------------
arch/x86/kvm/vmx.c | 2 +-
arch/x86/kvm/x86.c | 3 ++-
6 files changed, 30 insertions(+), 25 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 87ac4fb..7cbaab5 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1078,7 +1078,7 @@ void kvm_mmu_init_vm(struct kvm *kvm);
void kvm_mmu_uninit_vm(struct kvm *kvm);
void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
u64 dirty_mask, u64 nx_mask, u64 x_mask, u64 p_mask,
- u64 acc_track_mask);
+ u64 acc_track_mask, u64 me_mask);

void kvm_mmu_reset_context(struct kvm_vcpu *vcpu);
void kvm_mmu_slot_remove_write_access(struct kvm *kvm,
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index 9b1dd11..ccb70b8 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -108,7 +108,7 @@ module_param(dbg, bool, 0644);
(((address) >> PT32_LEVEL_SHIFT(level)) & ((1 << PT32_LEVEL_BITS) - 1))

-#define PT64_BASE_ADDR_MASK (((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1))
+#define PT64_BASE_ADDR_MASK __sme_clr((((1ULL << 52) - 1) & ~(u64)(PAGE_SIZE-1)))
#define PT64_DIR_BASE_ADDR_MASK \
(PT64_BASE_ADDR_MASK & ~((1ULL << (PAGE_SHIFT + PT64_LEVEL_BITS)) - 1))
#define PT64_LVL_ADDR_MASK(level) \
@@ -126,7 +126,7 @@ module_param(dbg, bool, 0644);
* PT32_LEVEL_BITS))) - 1))

#define PT64_PERM_MASK (PT_PRESENT_MASK | PT_WRITABLE_MASK | shadow_user_mask \
- | shadow_x_mask | shadow_nx_mask)
+ | shadow_x_mask | shadow_nx_mask | shadow_me_mask)

#define ACC_EXEC_MASK 1
#define ACC_WRITE_MASK PT_WRITABLE_MASK
@@ -186,6 +186,7 @@ static u64 __read_mostly shadow_dirty_mask;
static u64 __read_mostly shadow_mmio_mask;
static u64 __read_mostly shadow_mmio_value;
static u64 __read_mostly shadow_present_mask;
+static u64 __read_mostly shadow_me_mask;

/*
* SPTEs used by MMUs without A/D bits are marked with shadow_acc_track_value.
@@ -349,7 +350,7 @@ static bool check_mmio_spte(struct kvm_vcpu *vcpu, u64 spte)
*/
void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
u64 dirty_mask, u64 nx_mask, u64 x_mask, u64 p_mask,
- u64 acc_track_mask)
+ u64 acc_track_mask, u64 me_mask)
{
BUG_ON(!dirty_mask != !accessed_mask);
BUG_ON(!accessed_mask && !acc_track_mask);
@@ -362,6 +363,7 @@ void kvm_mmu_set_mask_ptes(u64 user_mask, u64 accessed_mask,
shadow_x_mask = x_mask;
shadow_present_mask = p_mask;
shadow_acc_track_mask = acc_track_mask;
+ shadow_me_mask = me_mask;
}
EXPORT_SYMBOL_GPL(kvm_mmu_set_mask_ptes);

@@ -2433,7 +2435,7 @@ static void link_shadow_page(struct kvm_vcpu *vcpu, u64 *sptep,
BUILD_BUG_ON(VMX_EPT_WRITABLE_MASK != PT_WRITABLE_MASK);

spte = __pa(sp->spt) | shadow_present_mask | PT_WRITABLE_MASK |
- shadow_user_mask | shadow_x_mask;
+ shadow_user_mask | shadow_x_mask | shadow_me_mask;

if (sp_ad_disabled(sp))
spte |= shadow_acc_track_value;
@@ -2745,6 +2747,7 @@ static int set_spte(struct kvm_vcpu *vcpu, u64 *sptep,
pte_access &= ~ACC_WRITE_MASK;

spte |= (u64)pfn << PAGE_SHIFT;
+ spte |= shadow_me_mask;

if (pte_access & ACC_WRITE_MASK) {

diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h
index d7d248a..3cc7255 100644
--- a/arch/x86/kvm/mmu.h
+++ b/arch/x86/kvm/mmu.h
@@ -48,7 +48,7 @@

static inline u64 rsvd_bits(int s, int e)
{
- return ((1ULL << (e - s + 1)) - 1) << s;
+ return __sme_clr(((1ULL << (e - s + 1)) - 1) << s);
}

void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask, u64 mmio_value);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 4d8141e..6af04dd 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1167,9 +1167,9 @@ static void avic_init_vmcb(struct vcpu_svm *svm)
{
struct vmcb *vmcb = svm->vmcb;
struct kvm_arch *vm_data = &svm->vcpu.kvm->arch;
- phys_addr_t bpa = page_to_phys(svm->avic_backing_page);
- phys_addr_t lpa = page_to_phys(vm_data->avic_logical_id_table_page);
- phys_addr_t ppa = page_to_phys(vm_data->avic_physical_id_table_page);
+ phys_addr_t bpa = __sme_set(page_to_phys(svm->avic_backing_page));
+ phys_addr_t lpa = __sme_set(page_to_phys(vm_data->avic_logical_id_table_page));
+ phys_addr_t ppa = __sme_set(page_to_phys(vm_data->avic_physical_id_table_page));

vmcb->control.avic_backing_page = bpa & AVIC_HPA_MASK;
vmcb->control.avic_logical_id = lpa & AVIC_HPA_MASK;
@@ -1232,8 +1232,8 @@ static void init_vmcb(struct vcpu_svm *svm)
set_intercept(svm, INTERCEPT_MWAIT);
}

- control->iopm_base_pa = iopm_base;
- control->msrpm_base_pa = __pa(svm->msrpm);
+ control->iopm_base_pa = __sme_set(iopm_base);
+ control->msrpm_base_pa = __sme_set(__pa(svm->msrpm));
control->int_ctl = V_INTR_MASKING_MASK;

init_seg(&save->es);
@@ -1377,9 +1377,9 @@ static int avic_init_backing_page(struct kvm_vcpu *vcpu)
return -EINVAL;

new_entry = READ_ONCE(*entry);
- new_entry = (page_to_phys(svm->avic_backing_page) &
- AVIC_PHYSICAL_ID_ENTRY_BACKING_PAGE_MASK) |
- AVIC_PHYSICAL_ID_ENTRY_VALID_MASK;
+ new_entry = __sme_set((page_to_phys(svm->avic_backing_page) &
+ AVIC_PHYSICAL_ID_ENTRY_BACKING_PAGE_MASK) |
+ AVIC_PHYSICAL_ID_ENTRY_VALID_MASK);
WRITE_ONCE(*entry, new_entry);

svm->avic_physical_id_cache = entry;
@@ -1647,7 +1647,7 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)

svm->vmcb = page_address(page);
clear_page(svm->vmcb);
- svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
+ svm->vmcb_pa = __sme_set(page_to_pfn(page) << PAGE_SHIFT);
svm->asid_generation = 0;
init_vmcb(svm);

@@ -1675,7 +1675,7 @@ static void svm_free_vcpu(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);

- __free_page(pfn_to_page(svm->vmcb_pa >> PAGE_SHIFT));
+ __free_page(pfn_to_page(__sme_clr(svm->vmcb_pa) >> PAGE_SHIFT));
__free_pages(virt_to_page(svm->msrpm), MSRPM_ALLOC_ORDER);
__free_page(virt_to_page(svm->nested.hsave));
__free_pages(virt_to_page(svm->nested.msrpm), MSRPM_ALLOC_ORDER);
@@ -2335,7 +2335,7 @@ static u64 nested_svm_get_tdp_pdptr(struct kvm_vcpu *vcpu, int index)
u64 pdpte;
int ret;

- ret = kvm_vcpu_read_guest_page(vcpu, gpa_to_gfn(cr3), &pdpte,
+ ret = kvm_vcpu_read_guest_page(vcpu, gpa_to_gfn(__sme_clr(cr3)), &pdpte,
offset_in_page(cr3) + index * 8, 8);
if (ret)
return 0;
@@ -2347,7 +2347,7 @@ static void nested_svm_set_tdp_cr3(struct kvm_vcpu *vcpu,
{
struct vcpu_svm *svm = to_svm(vcpu);

- svm->vmcb->control.nested_cr3 = root;
+ svm->vmcb->control.nested_cr3 = __sme_set(root);
mark_dirty(svm->vmcb, VMCB_NPT);
svm_flush_tlb(vcpu);
}
@@ -2868,7 +2868,7 @@ static bool nested_svm_vmrun_msrpm(struct vcpu_svm *svm)
svm->nested.msrpm[p] = svm->msrpm[p] | value;
}

- svm->vmcb->control.msrpm_base_pa = __pa(svm->nested.msrpm);
+ svm->vmcb->control.msrpm_base_pa = __sme_set(__pa(svm->nested.msrpm));

return true;
}
@@ -4501,7 +4501,7 @@ get_pi_vcpu_info(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e,
pr_debug("SVM: %s: use GA mode for irq %u\n", __func__,
irq.vector);
*svm = to_svm(vcpu);
- vcpu_info->pi_desc_addr = page_to_phys((*svm)->avic_backing_page);
+ vcpu_info->pi_desc_addr = __sme_set(page_to_phys((*svm)->avic_backing_page));
vcpu_info->vector = irq.vector;

return 0;
@@ -4552,7 +4552,8 @@ static int svm_update_pi_irte(struct kvm *kvm, unsigned int host_irq,
struct amd_iommu_pi_data pi;

/* Try to enable guest_mode in IRTE */
- pi.base = page_to_phys(svm->avic_backing_page) & AVIC_HPA_MASK;
+ pi.base = __sme_set(page_to_phys(svm->avic_backing_page) &
+ AVIC_HPA_MASK);
pi.ga_tag = AVIC_GATAG(kvm->arch.avic_vm_id,
svm->vcpu.vcpu_id);
pi.is_guest_mode = true;
@@ -5001,7 +5002,7 @@ static void svm_set_cr3(struct kvm_vcpu *vcpu, unsigned long root)
{
struct vcpu_svm *svm = to_svm(vcpu);

- svm->vmcb->save.cr3 = root;
+ svm->vmcb->save.cr3 = __sme_set(root);
mark_dirty(svm->vmcb, VMCB_CR);
svm_flush_tlb(vcpu);
}
@@ -5010,7 +5011,7 @@ static void set_tdp_cr3(struct kvm_vcpu *vcpu, unsigned long root)
{
struct vcpu_svm *svm = to_svm(vcpu);

- svm->vmcb->control.nested_cr3 = root;
+ svm->vmcb->control.nested_cr3 = __sme_set(root);
mark_dirty(svm->vmcb, VMCB_NPT);

/* Also sync guest cr3 here in case we live migrate */
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 84e62ac..ffd469e 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6492,7 +6492,7 @@ void vmx_enable_tdp(void)
enable_ept_ad_bits ? VMX_EPT_DIRTY_BIT : 0ull,
0ull, VMX_EPT_EXECUTABLE_MASK,
cpu_has_vmx_ept_execute_only() ? 0ull : VMX_EPT_READABLE_MASK,
- VMX_EPT_RWX_MASK);
+ VMX_EPT_RWX_MASK, 0ull);

ept_set_mmio_spte_mask();
kvm_enable_tdp();
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5b8f078..88be1aa 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -54,6 +54,7 @@
#include <linux/kvm_irqfd.h>
#include <linux/irqbypass.h>
#include <linux/sched/stat.h>
+#include <linux/mem_encrypt.h>

#include <trace/events/kvm.h>

@@ -6113,7 +6114,7 @@ int kvm_arch_init(void *opaque)

kvm_mmu_set_mask_ptes(PT_USER_MASK, PT_ACCESSED_MASK,
PT_DIRTY_MASK, PT64_NX_MASK, 0,
- PT_PRESENT_MASK, 0);
+ PT_PRESENT_MASK, 0, sme_me_mask);
kvm_timer_init();

perf_register_guest_info_callbacks(&kvm_guest_cbs);

Next message: tip-bot for Tom Lendacky: "[tip:x86/mm] x86/mm: Use proper encryption attributes with /dev/mem"
Previous message: tip-bot for Tom Lendacky: "[tip:x86/mm] x86, drm, fbdev: Do not specify encrypted memory for video mappings"
In reply to: Tom Lendacky: "[PATCH v10 30/38] kvm: x86: svm: Support Secure Memory Encryption within KVM"
Next in thread: Tom Lendacky: "[PATCH v10 29/38] x86, drm, fbdev: Do not specify encrypted memory for video mappings"
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