From: Rick Edgecombe <rick.p.edgecombe@intel.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
x86@kernel.org, linux-mm@kvack.org, luto@kernel.org,
peterz@infradead.org, dave.hansen@intel.com, pbonzini@redhat.com,
sean.j.christopherson@intel.com, keescook@chromium.org
Cc: kristen@linux.intel.com, deneen.t.dock@intel.com,
Rick Edgecombe <rick.p.edgecombe@intel.com>
Subject: [RFC PATCH 02/13] kvm: Add support for X86_FEATURE_KVM_XO
Date: Thu, 3 Oct 2019 14:23:49 -0700 [thread overview]
Message-ID: <20191003212400.31130-3-rick.p.edgecombe@intel.com> (raw)
In-Reply-To: <20191003212400.31130-1-rick.p.edgecombe@intel.com>
Add X86_FEATURE_KVM_XO which reduces the physical address bits exposed by
CPUID and uses the hosts highest physical address bit as an XO/NR
permission bit in the guest page tables. Adjust reserved mask so KVM guest
page tables walks are aware this bit is not reserved.
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
---
arch/x86/include/asm/cpufeature.h | 1 +
arch/x86/include/asm/cpufeatures.h | 3 +++
arch/x86/include/uapi/asm/kvm_para.h | 3 +++
arch/x86/kvm/cpuid.c | 7 +++++++
arch/x86/kvm/cpuid.h | 1 +
arch/x86/kvm/mmu.c | 18 ++++++++++++------
6 files changed, 27 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 58acda503817..17127ffbc2a2 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -30,6 +30,7 @@ enum cpuid_leafs
CPUID_7_ECX,
CPUID_8000_0007_EBX,
CPUID_7_EDX,
+ CPUID_4000_0030_EAX
};
#ifdef CONFIG_X86_FEATURE_NAMES
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index e880f2408e29..7ba217e894ea 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -364,6 +364,9 @@
#define X86_FEATURE_ARCH_CAPABILITIES (18*32+29) /* IA32_ARCH_CAPABILITIES MSR (Intel) */
#define X86_FEATURE_SPEC_CTRL_SSBD (18*32+31) /* "" Speculative Store Bypass Disable */
+/* KVM-defined CPU features, CPUID level 0x40000030 (EAX), word 19 */
+#define X86_FEATURE_KVM_XO (19*32+0) /* KVM EPT based execute only memory support */
+
/*
* BUG word(s)
*/
diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
index 2a8e0b6b9805..ecff0ff25cf4 100644
--- a/arch/x86/include/uapi/asm/kvm_para.h
+++ b/arch/x86/include/uapi/asm/kvm_para.h
@@ -34,6 +34,9 @@
#define KVM_HINTS_REALTIME 0
+#define KVM_CPUID_FEAT_GENERIC 0x40000030
+#define KVM_FEATURE_GENERIC_XO 0
+
/* The last 8 bits are used to indicate how to interpret the flags field
* in pvclock structure. If no bits are set, all flags are ignored.
*/
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 22c2720cd948..bcbf3f93602d 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -700,6 +700,12 @@ static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
if (sched_info_on())
entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
+ entry->ebx = 0;
+ entry->ecx = 0;
+ entry->edx = 0;
+ break;
+ case KVM_CPUID_FEAT_GENERIC:
+ entry->eax = (1 << KVM_FEATURE_GENERIC_XO);
entry->ebx = 0;
entry->ecx = 0;
entry->edx = 0;
@@ -845,6 +851,7 @@ int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
{ .func = 0x80000000 },
{ .func = 0xC0000000, .qualifier = is_centaur_cpu },
{ .func = KVM_CPUID_SIGNATURE },
+ { .func = KVM_CPUID_FEAT_GENERIC },
};
if (cpuid->nent < 1)
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index d78a61408243..c36d462a0e01 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -53,6 +53,7 @@ static const struct cpuid_reg reverse_cpuid[] = {
[CPUID_7_ECX] = { 7, 0, CPUID_ECX},
[CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
[CPUID_7_EDX] = { 7, 0, CPUID_EDX},
+ [CPUID_4000_0030_EAX] = {0x40000030, 0, CPUID_EAX},
};
static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned x86_feature)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
index a63964e7cec7..e44a8053af78 100644
--- a/arch/x86/kvm/mmu.c
+++ b/arch/x86/kvm/mmu.c
@@ -4358,12 +4358,15 @@ static void
__reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
struct rsvd_bits_validate *rsvd_check,
int maxphyaddr, int level, bool nx, bool gbpages,
- bool pse, bool amd)
+ bool pse, bool amd, bool xo)
{
u64 exb_bit_rsvd = 0;
u64 gbpages_bit_rsvd = 0;
u64 nonleaf_bit8_rsvd = 0;
+ /* Adjust maxphyaddr to include the XO bit if in use */
+ maxphyaddr += xo;
+
rsvd_check->bad_mt_xwr = 0;
if (!nx)
@@ -4448,10 +4451,12 @@ static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu,
struct kvm_mmu *context)
{
__reset_rsvds_bits_mask(vcpu, &context->guest_rsvd_check,
- cpuid_maxphyaddr(vcpu), context->root_level,
+ cpuid_maxphyaddr(vcpu),
+ context->root_level,
context->nx,
guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES),
- is_pse(vcpu), guest_cpuid_is_amd(vcpu));
+ is_pse(vcpu), guest_cpuid_is_amd(vcpu),
+ guest_cpuid_has(vcpu, X86_FEATURE_KVM_XO));
}
static void
@@ -4520,7 +4525,7 @@ reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context)
shadow_phys_bits,
context->shadow_root_level, uses_nx,
guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES),
- is_pse(vcpu), true);
+ is_pse(vcpu), true, false);
if (!shadow_me_mask)
return;
@@ -4557,7 +4562,7 @@ reset_tdp_shadow_zero_bits_mask(struct kvm_vcpu *vcpu,
shadow_phys_bits,
context->shadow_root_level, false,
boot_cpu_has(X86_FEATURE_GBPAGES),
- true, true);
+ true, true, false);
else
__reset_rsvds_bits_mask_ept(shadow_zero_check,
shadow_phys_bits,
@@ -4818,7 +4823,8 @@ static union kvm_mmu_extended_role kvm_calc_mmu_role_ext(struct kvm_vcpu *vcpu)
ext.cr4_pse = !!is_pse(vcpu);
ext.cr4_pke = !!kvm_read_cr4_bits(vcpu, X86_CR4_PKE);
ext.cr4_la57 = !!kvm_read_cr4_bits(vcpu, X86_CR4_LA57);
- ext.maxphyaddr = cpuid_maxphyaddr(vcpu);
+ ext.maxphyaddr = cpuid_maxphyaddr(vcpu)
+ + guest_cpuid_has(vcpu, X86_FEATURE_KVM_XO);
ext.valid = 1;
--
2.17.1
next prev parent reply other threads:[~2019-10-03 21:39 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-03 21:23 [RFC PATCH 00/13] XOM for KVM guest userspace Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 01/13] kvm: Enable MTRR to work with GFNs with perm bits Rick Edgecombe
2019-10-14 6:47 ` Yu Zhang
2019-10-14 18:44 ` Edgecombe, Rick P
2019-10-03 21:23 ` Rick Edgecombe [this message]
2019-10-03 21:23 ` [RFC PATCH 03/13] kvm: Add XO memslot type Rick Edgecombe
2019-10-04 7:27 ` Paolo Bonzini
2019-10-04 19:06 ` Edgecombe, Rick P
2019-10-06 16:15 ` Paolo Bonzini
2019-10-03 21:23 ` [RFC PATCH 04/13] kvm, vmx: Add support for gva exit qualification Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 05/13] kvm: Add #PF injection for KVM XO Rick Edgecombe
2019-10-04 7:42 ` Paolo Bonzini
2019-10-04 19:11 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 06/13] kvm: Add KVM_CAP_EXECONLY_MEM Rick Edgecombe
2019-10-04 7:24 ` Paolo Bonzini
2019-10-04 19:11 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 07/13] kvm: Add docs for KVM_CAP_EXECONLY_MEM Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 08/13] x86/boot: Rename USE_EARLY_PGTABLE_L5 Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 09/13] x86/cpufeature: Add detection of KVM XO Rick Edgecombe
2019-10-29 23:33 ` Kees Cook
2019-10-29 23:52 ` Edgecombe, Rick P
2019-10-30 14:55 ` Sean Christopherson
2019-10-30 21:02 ` Edgecombe, Rick P
2019-10-03 21:23 ` [RFC PATCH 10/13] x86/mm: Add NR page bit for " Rick Edgecombe
2019-10-04 7:33 ` Paolo Bonzini
2019-10-03 21:23 ` [RFC PATCH 11/13] x86, ptdump: Add NR bit to page table dump Rick Edgecombe
2019-10-03 21:23 ` [RFC PATCH 12/13] mmap: Add XO support for KVM XO Rick Edgecombe
2019-10-04 7:34 ` Paolo Bonzini
2019-10-04 19:12 ` Edgecombe, Rick P
2019-10-03 21:24 ` [RFC PATCH 13/13] x86/Kconfig: Add Kconfig for KVM based XO Rick Edgecombe
2019-10-29 23:36 ` Kees Cook
2019-10-30 0:01 ` Edgecombe, Rick P
2019-10-30 18:36 ` Kees Cook
2019-10-04 7:22 ` [RFC PATCH 00/13] XOM for KVM guest userspace Paolo Bonzini
2019-10-04 19:03 ` Edgecombe, Rick P
2019-10-04 14:56 ` Andy Lutomirski
2019-10-04 20:09 ` Edgecombe, Rick P
2019-10-05 1:33 ` Andy Lutomirski
2019-10-07 18:14 ` Edgecombe, Rick P
2019-10-29 23:40 ` Kees Cook
2019-10-30 0:27 ` Edgecombe, Rick P
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