From: Brijesh Singh <brijesh.singh@amd.com>
To: Peter Gonda <pgonda@google.com>
Cc: brijesh.singh@amd.com, x86@kernel.org,
linux-kernel@vger.kernel.org, kvm list <kvm@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>,
jroedel@suse.de, "Lendacky, Thomas" <thomas.lendacky@amd.com>,
Paolo Bonzini <pbonzini@redhat.com>,
Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@intel.com>,
David Rientjes <rientjes@google.com>,
Sean Christopherson <seanjc@google.com>,
peterz@infradead.org, "H. Peter Anvin" <hpa@zytor.com>,
tony.luck@intel.com
Subject: Re: [PATCH Part2 RFC v2 36/37] KVM: SVM: Provide support for SNP_GUEST_REQUEST NAE event
Date: Mon, 10 May 2021 15:14:07 -0500 [thread overview]
Message-ID: <f357d874-a369-93b6-ffa1-75c643596c81@amd.com> (raw)
In-Reply-To: <CAMkAt6ottZkx02-ykazkG-5Tu5URv-xwOjWOZ=XMAXv98_HOYA@mail.gmail.com>
On 5/10/21 1:57 PM, Peter Gonda wrote:
>> +static void snp_handle_guest_request(struct vcpu_svm *svm, struct ghcb *ghcb,
>> + gpa_t req_gpa, gpa_t resp_gpa)
>> +{
>> + struct sev_data_snp_guest_request data = {};
>> + struct kvm_vcpu *vcpu = &svm->vcpu;
>> + struct kvm *kvm = vcpu->kvm;
>> + kvm_pfn_t req_pfn, resp_pfn;
>> + struct kvm_sev_info *sev;
>> + int rc, err = 0;
>> +
>> + if (!sev_snp_guest(vcpu->kvm)) {
>> + rc = -ENODEV;
>> + goto e_fail;
>> + }
>> +
>> + sev = &to_kvm_svm(kvm)->sev_info;
>> +
>> + if (!__ratelimit(&sev->snp_guest_msg_rs)) {
>> + pr_info_ratelimited("svm: too many guest message requests\n");
>> + rc = -EAGAIN;
>> + goto e_fail;
>> + }
>> +
>> + if (!IS_ALIGNED(req_gpa, PAGE_SIZE) || !IS_ALIGNED(resp_gpa, PAGE_SIZE)) {
>> + pr_err("svm: guest request (%#llx) or response (%#llx) is not page aligned\n",
>> + req_gpa, resp_gpa);
>> + goto e_term;
>> + }
>> +
>> + req_pfn = gfn_to_pfn(kvm, gpa_to_gfn(req_gpa));
>> + if (is_error_noslot_pfn(req_pfn)) {
>> + pr_err("svm: guest request invalid gpa=%#llx\n", req_gpa);
>> + goto e_term;
>> + }
>> +
>> + resp_pfn = gfn_to_pfn(kvm, gpa_to_gfn(resp_gpa));
>> + if (is_error_noslot_pfn(resp_pfn)) {
>> + pr_err("svm: guest response invalid gpa=%#llx\n", resp_gpa);
>> + goto e_term;
>> + }
>> +
>> + data.gctx_paddr = __psp_pa(sev->snp_context);
>> + data.req_paddr = __sme_set(req_pfn << PAGE_SHIFT);
>> + data.res_paddr = __psp_pa(sev->snp_resp_page);
>> +
>> + mutex_lock(&kvm->lock);
>> +
>> + rc = sev_issue_cmd(kvm, SEV_CMD_SNP_GUEST_REQUEST, &data, &err);
>> + if (rc) {
>> + mutex_unlock(&kvm->lock);
>> +
>> + /* If we have a firmware error code then use it. */
>> + if (err)
>> + rc = err;
>> +
>> + goto e_fail;
>> + }
>> +
>> + /* Copy the response after the firmware returns success. */
>> + rc = kvm_write_guest(kvm, resp_gpa, sev->snp_resp_page, PAGE_SIZE);
>> +
>> + mutex_unlock(&kvm->lock);
>> +
>> +e_fail:
>> + ghcb_set_sw_exit_info_2(ghcb, rc);
>> + return;
>> +
>> +e_term:
>> + ghcb_set_sw_exit_info_1(ghcb, 1);
>> + ghcb_set_sw_exit_info_2(ghcb,
>> + X86_TRAP_GP |
>> + SVM_EVTINJ_TYPE_EXEPT |
>> + SVM_EVTINJ_VALID);
>> +}
> I am probably missing something in the spec but I don't see any
> references to #GP in the '4.1.7 SNP Guest Request' section. Why is
> this different from e_fail?
The spec does not say to inject the #GP, I chose this because guest is
not adhering to the spec and there was a not a good error code in the
GHCB spec to communicate this condition. Per the spec, both the request
and response page must be a valid GPA. If we detect that guest is not
following the spec then its a guest BUG. IIRC, other places in the KVM
does something similar when guest is trying invalid operation.
-Brijesh
next prev parent reply other threads:[~2021-05-10 20:14 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-30 12:37 [PATCH Part2 RFC v2 00/37] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 01/37] KVM: SVM: Add support to handle AP reset MSR protocol Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 02/37] KVM: SVM: Provide the Hypervisor Feature support VMGEXIT Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 03/37] KVM: SVM: Increase the GHCB protocol version Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 04/37] x86/cpufeatures: Add SEV-SNP CPU feature Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 05/37] x86/sev: Add the host SEV-SNP initialization support Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 06/37] x86/sev: Add RMP entry lookup helpers Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 07/37] x86/sev: Add helper functions for RMPUPDATE and PSMASH instruction Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 08/37] x86/sev: Split the physmap when adding the page in RMP table Brijesh Singh
2021-05-03 15:07 ` Peter Zijlstra
2021-05-03 15:15 ` Andy Lutomirski
2021-05-03 15:41 ` Dave Hansen
2021-05-07 11:28 ` Vlastimil Babka
2021-04-30 12:37 ` [PATCH Part2 RFC v2 09/37] x86/traps: Define RMP violation #PF error code Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 10/37] x86/fault: Add support to handle the RMP fault for kernel address Brijesh Singh
2021-05-03 14:44 ` Dave Hansen
2021-05-03 15:03 ` Andy Lutomirski
2021-05-03 15:49 ` Brijesh Singh
2021-05-03 15:37 ` Brijesh Singh
2021-05-03 16:15 ` Dave Hansen
2021-05-03 17:19 ` Brijesh Singh
2021-05-03 17:31 ` Brijesh Singh
2021-05-03 17:40 ` Andy Lutomirski
2021-05-03 19:41 ` Brijesh Singh
2021-05-03 19:43 ` Dave Hansen
2021-05-04 12:31 ` Brijesh Singh
2021-05-04 14:33 ` Dave Hansen
2021-05-04 15:16 ` Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 11/37] x86/fault: Add support to handle the RMP fault for user address Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 12/37] crypto:ccp: Define the SEV-SNP commands Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 13/37] crypto: ccp: Add support to initialize the AMD-SP for SEV-SNP Brijesh Singh
2021-04-30 12:37 ` [PATCH Part2 RFC v2 14/37] crypto: ccp: Shutdown SNP firmware on kexec Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 15/37] crypto:ccp: Provide APIs to issue SEV-SNP commands Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 16/37] crypto: ccp: Handle the legacy TMR allocation when SNP is enabled Brijesh Singh
2021-05-10 18:23 ` Peter Gonda
2021-05-10 20:07 ` Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 17/37] crypto: ccp: Handle the legacy SEV command " Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 18/37] KVM: SVM: make AVIC backing, VMSA and VMCB memory allocation SNP safe Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 19/37] KVM: SVM: Add initial SEV-SNP support Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 20/37] KVM: SVM: define new SEV_FEATURES field in the VMCB Save State Area Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 21/37] KVM: SVM: Add KVM_SNP_INIT command Brijesh Singh
2021-05-06 20:25 ` Peter Gonda
2021-05-06 22:29 ` Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 22/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_START command Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 23/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_UPDATE command Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 24/37] KVM: SVM: Reclaim the guest pages when SEV-SNP VM terminates Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 25/37] KVM: SVM: Add KVM_SEV_SNP_LAUNCH_FINISH command Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 26/37] KVM: X86: Add kvm_x86_ops to get the max page level for the TDP Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 27/37] KVM: X86: Introduce kvm_mmu_map_tdp_page() for use by SEV Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 28/37] KVM: X86: Introduce kvm_mmu_get_tdp_walk() for SEV-SNP use Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 29/37] KVM: X86: Define new RMP check related #NPF error bits Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 30/37] KVM: X86: update page-fault trace to log the 64-bit error code Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 31/37] KVM: SVM: Add support to handle GHCB GPA register VMGEXIT Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 32/37] KVM: SVM: Add support to handle MSR based Page State Change VMGEXIT Brijesh Singh
2021-05-10 17:30 ` Peter Gonda
2021-05-10 17:51 ` Brijesh Singh
2021-05-10 19:59 ` Peter Gonda
2021-05-10 20:50 ` Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 33/37] KVM: SVM: Add support to handle " Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 34/37] KVM: X86: Export the kvm_zap_gfn_range() for the SNP use Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 35/37] KVM: SVM: Add support to handle the RMP nested page fault Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 36/37] KVM: SVM: Provide support for SNP_GUEST_REQUEST NAE event Brijesh Singh
2021-05-10 18:57 ` Peter Gonda
2021-05-10 20:14 ` Brijesh Singh [this message]
2021-05-10 21:17 ` Sean Christopherson
2021-05-11 18:34 ` Brijesh Singh
2021-04-30 12:38 ` [PATCH Part2 RFC v2 37/37] KVM: SVM: Advertise the SEV-SNP feature support Brijesh Singh
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