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From: Brijesh Singh <brijesh.singh@amd.com>
To: x86@kernel.org, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, linux-coco@lists.linux.dev,
	linux-mm@kvack.org, linux-crypto@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Ard Biesheuvel <ardb@kernel.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Sean Christopherson <seanjc@google.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Wanpeng Li <wanpengli@tencent.com>,
	Jim Mattson <jmattson@google.com>,
	Andy Lutomirski <luto@kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Sergio Lopez <slp@redhat.com>, Peter Gonda <pgonda@google.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	David Rientjes <rientjes@google.com>,
	tony.luck@intel.com, npmccallum@redhat.com,
	Borislav Petkov <bp@suse.de>,
	Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH Part2 RFC v3 24/37] KVM: X86: Add kvm_x86_ops to get the max page level for the TDP
Date: Wed,  2 Jun 2021 09:10:44 -0500	[thread overview]
Message-ID: <20210602141057.27107-25-brijesh.singh@amd.com> (raw)
In-Reply-To: <20210602141057.27107-1-brijesh.singh@amd.com>

When running an SEV-SNP VM, the sPA used to index the RMP entry is
obtained through the TDP translation (gva->gpa->spa). The TDP page
level is checked against the page level programmed in the RMP entry.
If the page level does not match, then it will cause a nested page
fault with the RMP bit set to indicate the RMP violation.

To keep the TDP and RMP page level's in sync, the KVM fault handle
kvm_handle_page_fault() will call get_tdp_max_page_level() to get
the maximum allowed page level so that it can limit the TDP level.

In the case of SEV-SNP guest, the get_tdp_max_page_level() will consult
the RMP table to compute the maximum allowed page level for a given
GPA.

Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
 arch/x86/include/asm/kvm_host.h |  1 +
 arch/x86/kvm/mmu/mmu.c          |  6 ++++--
 arch/x86/kvm/svm/sev.c          | 20 ++++++++++++++++++++
 arch/x86/kvm/svm/svm.c          |  1 +
 arch/x86/kvm/svm/svm.h          |  1 +
 arch/x86/kvm/vmx/vmx.c          |  8 ++++++++
 6 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 188110ab2c02..cd2e19e1d323 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1384,6 +1384,7 @@ struct kvm_x86_ops {
 
 	void (*vcpu_deliver_sipi_vector)(struct kvm_vcpu *vcpu, u8 vector);
 	void *(*alloc_apic_backing_page)(struct kvm_vcpu *vcpu);
+	int (*get_tdp_max_page_level)(struct kvm_vcpu *vcpu, gpa_t gpa, int max_level);
 };
 
 struct kvm_x86_nested_ops {
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 0144c40d09c7..7991ffae7b31 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3781,11 +3781,13 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa,
 				u32 error_code, bool prefault)
 {
+	int max_level = kvm_x86_ops.get_tdp_max_page_level(vcpu, gpa, PG_LEVEL_2M);
+
 	pgprintk("%s: gva %lx error %x\n", __func__, gpa, error_code);
 
 	/* This path builds a PAE pagetable, we can map 2mb pages at maximum. */
 	return direct_page_fault(vcpu, gpa & PAGE_MASK, error_code, prefault,
-				 PG_LEVEL_2M, false);
+				 max_level, false);
 }
 
 int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
@@ -3826,7 +3828,7 @@ int kvm_tdp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
 {
 	int max_level;
 
-	for (max_level = KVM_MAX_HUGEPAGE_LEVEL;
+	for (max_level = kvm_x86_ops.get_tdp_max_page_level(vcpu, gpa, KVM_MAX_HUGEPAGE_LEVEL);
 	     max_level > PG_LEVEL_4K;
 	     max_level--) {
 		int page_num = KVM_PAGES_PER_HPAGE(max_level);
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 856a6cf99a61..6b0c230c5f37 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3184,3 +3184,23 @@ struct page *snp_safe_alloc_page(struct kvm_vcpu *vcpu)
 
 	return pfn_to_page(pfn);
 }
+
+int sev_get_tdp_max_page_level(struct kvm_vcpu *vcpu, gpa_t gpa, int max_level)
+{
+	struct rmpentry *e;
+	kvm_pfn_t pfn;
+	int level;
+
+	if (!sev_snp_guest(vcpu->kvm))
+		return max_level;
+
+	pfn = gfn_to_pfn(vcpu->kvm, gpa_to_gfn(gpa));
+	if (is_error_noslot_pfn(pfn))
+		return max_level;
+
+	e = snp_lookup_page_in_rmptable(pfn_to_page(pfn), &level);
+	if (unlikely(!e))
+		return max_level;
+
+	return min_t(uint32_t, level, max_level);
+}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index a7adf6ca1713..2632eae52aa3 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4576,6 +4576,7 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
 	.vcpu_deliver_sipi_vector = svm_vcpu_deliver_sipi_vector,
 
 	.alloc_apic_backing_page = svm_alloc_apic_backing_page,
+	.get_tdp_max_page_level = sev_get_tdp_max_page_level,
 };
 
 static struct kvm_x86_init_ops svm_init_ops __initdata = {
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index bc5582b44356..32abcbd774d0 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -568,6 +568,7 @@ void sev_vcpu_deliver_sipi_vector(struct kvm_vcpu *vcpu, u8 vector);
 void sev_es_prepare_guest_switch(struct vcpu_svm *svm, unsigned int cpu);
 void sev_es_unmap_ghcb(struct vcpu_svm *svm);
 struct page *snp_safe_alloc_page(struct kvm_vcpu *vcpu);
+int sev_get_tdp_max_page_level(struct kvm_vcpu *vcpu, gpa_t gpa, int max_level);
 
 /* vmenter.S */
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 4bceb5ca3a89..fbc9034edf16 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -7612,6 +7612,12 @@ static bool vmx_check_apicv_inhibit_reasons(ulong bit)
 	return supported & BIT(bit);
 }
 
+
+static int vmx_get_tdp_max_page_level(struct kvm_vcpu *vcpu, gpa_t gpa, int max_level)
+{
+	return max_level;
+}
+
 static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.hardware_unsetup = hardware_unsetup,
 
@@ -7742,6 +7748,8 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
 	.complete_emulated_msr = kvm_complete_insn_gp,
 
 	.vcpu_deliver_sipi_vector = kvm_vcpu_deliver_sipi_vector,
+
+	.get_tdp_max_page_level = vmx_get_tdp_max_page_level,
 };
 
 static __init void vmx_setup_user_return_msrs(void)
-- 
2.17.1


  parent reply	other threads:[~2021-06-02 14:12 UTC|newest]

Thread overview: 40+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-02 14:10 [PATCH Part2 RFC v3 00/37] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 01/37] KVM: SVM: Add support to handle AP reset MSR protocol Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 02/37] KVM: SVM: Provide the Hypervisor Feature support VMGEXIT Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 03/37] x86/cpufeatures: Add SEV-SNP CPU feature Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 04/37] x86/sev: Add the host SEV-SNP initialization support Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 05/37] x86/sev: Add RMP entry lookup helpers Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 06/37] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction Brijesh Singh
2021-06-10 13:03   ` Dr. David Alan Gilbert
2021-06-02 14:10 ` [PATCH Part2 RFC v3 07/37] x86/sev: Split the physmap when adding the page in RMP table Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 08/37] x86/traps: Define RMP violation #PF error code Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 09/37] x86/fault: Add support to dump RMP entry on fault Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 10/37] x86/fault: Add support to handle the RMP fault for user address Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 11/37] crypto:ccp: Define the SEV-SNP commands Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 12/37] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 13/37] crypto: ccp: Shutdown SNP firmware on kexec Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 14/37] crypto:ccp: Provide APIs to issue SEV-SNP commands Brijesh Singh
2021-06-15 11:23   ` Dr. David Alan Gilbert
2021-06-02 14:10 ` [PATCH Part2 RFC v3 15/37] crypto: ccp: Handle the legacy TMR allocation when SNP is enabled Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 16/37] crypto: ccp: Handle the legacy SEV command " Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 17/37] KVM: SVM: make AVIC backing, VMSA and VMCB memory allocation SNP safe Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 18/37] KVM: SVM: Add initial SEV-SNP support Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 19/37] KVM: SVM: Add KVM_SNP_INIT command Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 20/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_START command Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 21/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_UPDATE command Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 22/37] KVM: SVM: Reclaim the guest pages when SEV-SNP VM terminates Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 23/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_FINISH command Brijesh Singh
2021-06-02 14:10 ` Brijesh Singh [this message]
2021-06-02 14:10 ` [PATCH Part2 RFC v3 25/37] KVM: X86: Introduce kvm_mmu_map_tdp_page() for use by SEV Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 26/37] KVM: X86: Introduce kvm_mmu_get_tdp_walk() for SEV-SNP use Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 27/37] KVM: X86: Define new RMP check related #NPF error bits Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 28/37] KVM: X86: update page-fault trace to log the 64-bit error code Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 29/37] KVM: SVM: Add support to handle GHCB GPA register VMGEXIT Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 30/37] KVM: SVM: Add support to handle MSR based Page State Change VMGEXIT Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 31/37] KVM: SVM: Add support to handle " Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 32/37] KVM: Add arch hooks to track the host write to guest memory Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 33/37] KVM: X86: Export the kvm_zap_gfn_range() for the SNP use Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 34/37] KVM: SVM: Add support to handle the RMP nested page fault Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 35/37] KVM: SVM: Provide support for SNP_GUEST_REQUEST NAE event Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 36/37] KVM: SVM: Use a VMSA physical address variable for populating VMCB Brijesh Singh
2021-06-02 14:10 ` [PATCH Part2 RFC v3 37/37] KVM: SVM: Support SEV-SNP AP Creation NAE event Brijesh Singh

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