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 34/37] KVM: SVM: Add support to handle the RMP nested page fault
Date: Wed, 2 Jun 2021 09:10:54 -0500 [thread overview]
Message-ID: <20210602141057.27107-35-brijesh.singh@amd.com> (raw)
In-Reply-To: <20210602141057.27107-1-brijesh.singh@amd.com>
Follow the recommendation from APM2 section 15.36.10 and 15.36.11 to
resolve the RMP violation encountered during the NPT table walk.
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
arch/x86/include/asm/kvm_host.h | 3 ++
arch/x86/kvm/mmu/mmu.c | 20 ++++++++++++
arch/x86/kvm/svm/sev.c | 57 +++++++++++++++++++++++++++++++++
arch/x86/kvm/svm/svm.c | 2 ++
arch/x86/kvm/svm/svm.h | 2 ++
5 files changed, 84 insertions(+)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 46323af09995..117e2e08d7ed 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1399,6 +1399,9 @@ struct kvm_x86_ops {
void (*write_page_begin)(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn);
void (*write_page_end)(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn);
+
+ int (*handle_rmp_page_fault)(struct kvm_vcpu *vcpu, gpa_t gpa, kvm_pfn_t pfn,
+ int level, u64 error_code);
};
struct kvm_x86_nested_ops {
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e60f54455cdc..b6a676ba1862 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5096,6 +5096,18 @@ static void kvm_mmu_pte_write(struct kvm_vcpu *vcpu, gpa_t gpa,
write_unlock(&vcpu->kvm->mmu_lock);
}
+static int handle_rmp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code)
+{
+ kvm_pfn_t pfn;
+ int level;
+
+ if (unlikely(!kvm_mmu_get_tdp_walk(vcpu, gpa, &pfn, &level)))
+ return RET_PF_RETRY;
+
+ kvm_x86_ops.handle_rmp_page_fault(vcpu, gpa, pfn, level, error_code);
+ return RET_PF_RETRY;
+}
+
int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
void *insn, int insn_len)
{
@@ -5112,6 +5124,14 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa, u64 error_code,
goto emulate;
}
+ if (unlikely(error_code & PFERR_GUEST_RMP_MASK)) {
+ r = handle_rmp_page_fault(vcpu, cr2_or_gpa, error_code);
+ if (r == RET_PF_RETRY)
+ return 1;
+ else
+ return r;
+ }
+
if (r == RET_PF_INVALID) {
r = kvm_mmu_do_page_fault(vcpu, cr2_or_gpa,
lower_32_bits(error_code), false);
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index d30419e91288..5b033d4c3b92 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -3497,3 +3497,60 @@ void sev_snp_write_page_begin(struct kvm *kvm, struct kvm_memory_slot *slot, gfn
BUG_ON(rc != 0);
}
}
+
+int snp_handle_rmp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, kvm_pfn_t pfn,
+ int level, u64 error_code)
+{
+ struct rmpentry *e;
+ int rlevel, rc = 0;
+ bool private;
+ gfn_t gfn;
+
+ e = snp_lookup_page_in_rmptable(pfn_to_page(pfn), &rlevel);
+ if (!e)
+ return 1;
+
+ private = !!(error_code & PFERR_GUEST_ENC_MASK);
+
+ /*
+ * See APM section 15.36.11 on how to handle the RMP fault for the large pages.
+ *
+ * npt rmp access action
+ * --------------------------------------------------
+ * 4k 2M C=1 psmash
+ * x x C=1 if page is not private then add a new RMP entry
+ * x x C=0 if page is private then make it shared
+ * 2M 4k C=x zap
+ */
+ if ((error_code & PFERR_GUEST_SIZEM_MASK) ||
+ ((level == PG_LEVEL_4K) && (rlevel == PG_LEVEL_2M) && private)) {
+ rc = snp_rmptable_psmash(vcpu, pfn);
+ goto zap_gfn;
+ }
+
+ /*
+ * If it's a private access, and the page is not assigned in the RMP table, create a
+ * new private RMP entry.
+ */
+ if (!rmpentry_assigned(e) && private) {
+ rc = snp_make_page_private(vcpu, gpa, pfn, PG_LEVEL_4K);
+ goto zap_gfn;
+ }
+
+ /*
+ * If it's a shared access, then make the page shared in the RMP table.
+ */
+ if (rmpentry_assigned(e) && !private)
+ rc = snp_make_page_shared(vcpu, gpa, pfn, PG_LEVEL_4K);
+
+zap_gfn:
+ /*
+ * Now that we have updated the RMP pagesize, zap the existing rmaps for
+ * large entry ranges so that nested page table gets rebuilt with the updated RMP
+ * pagesize.
+ */
+ gfn = gpa_to_gfn(gpa) & ~(KVM_PAGES_PER_HPAGE(PG_LEVEL_2M) - 1);
+ kvm_zap_gfn_range(vcpu->kvm, gfn, gfn + 512);
+
+ return 0;
+}
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 4ff6fc86dd18..32e35d396508 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4579,6 +4579,8 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.get_tdp_max_page_level = sev_get_tdp_max_page_level,
.write_page_begin = sev_snp_write_page_begin,
+
+ .handle_rmp_page_fault = snp_handle_rmp_page_fault,
};
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 e0276ad8a1ae..ccdaaa4e1fb1 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -577,6 +577,8 @@ 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);
void sev_snp_write_page_begin(struct kvm *kvm, struct kvm_memory_slot *slot, gfn_t gfn);
+int snp_handle_rmp_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, kvm_pfn_t pfn,
+ int level, u64 error_code);
/* vmenter.S */
--
2.17.1
next prev parent reply other threads:[~2021-06-02 14:16 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 ` [PATCH Part2 RFC v3 24/37] KVM: X86: Add kvm_x86_ops to get the max page level for the TDP Brijesh Singh
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 ` Brijesh Singh [this message]
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
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210602141057.27107-35-brijesh.singh@amd.com \
--to=brijesh.singh@amd.com \
--cc=ardb@kernel.org \
--cc=bp@suse.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jmattson@google.com \
--cc=jroedel@suse.de \
--cc=kvm@vger.kernel.org \
--cc=linux-coco@lists.linux.dev \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=luto@kernel.org \
--cc=mingo@redhat.com \
--cc=npmccallum@redhat.com \
--cc=pbonzini@redhat.com \
--cc=peterz@infradead.org \
--cc=pgonda@google.com \
--cc=rientjes@google.com \
--cc=seanjc@google.com \
--cc=slp@redhat.com \
--cc=srinivas.pandruvada@linux.intel.com \
--cc=tglx@linutronix.de \
--cc=thomas.lendacky@amd.com \
--cc=tony.luck@intel.com \
--cc=vkuznets@redhat.com \
--cc=wanpengli@tencent.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).