From: Sean Christopherson Date: Fri, 29 May 2026 18:35:37 +0000 (+0200) Subject: KVM: SEV: Add an anonymous "psc" struct to track current PSC metadata X-Git-Tag: v7.1-rc7~14^2~7 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=00b9744a3688758c5c492756d08a1cd599a76965;p=thirdparty%2Flinux.git KVM: SEV: Add an anonymous "psc" struct to track current PSC metadata Add a "psc" struct to vcpu_sev_es_state to avoid having to prefix all of the fields with "psc_". Take advantage of the code churn to opportunistically rename local variables to "guest_psc" to make it more obvious that the buffer is guest data, and more importantly, guest accessible! Opportunistically rename inflight => batch_size as well, because there can really only be one operation in-flight (per-vCPU), i.e. "inflight" _looks_ like a boolean, but in actuality is an integer tracking how many pages are being handled by the current operation. No functional change intended. Reviewed-by: Tom Lendacky Signed-off-by: Sean Christopherson Message-ID: <20260501202250.2115252-13-seanjc@google.com> Signed-off-by: Paolo Bonzini Message-ID: <20260529183549.1104619-13-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 1982d13e71d9e..9f6543cebedf5 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -3845,9 +3845,7 @@ static int snp_begin_psc(struct vcpu_svm *svm); static void snp_complete_psc(struct vcpu_svm *svm, u64 psc_ret) { - svm->sev_es.psc_inflight = 0; - svm->sev_es.psc_idx = 0; - svm->sev_es.psc_2m = false; + memset(&svm->sev_es.psc, 0, sizeof(svm->sev_es.psc)); /* * PSC requests always get a "no action" response in SW_EXITINFO1, with @@ -3860,9 +3858,8 @@ static void snp_complete_psc(struct vcpu_svm *svm, u64 psc_ret) static void __snp_complete_one_psc(struct vcpu_svm *svm) { - struct psc_buffer *psc = svm->sev_es.ghcb_sa; - struct psc_entry *entries = psc->entries; - struct psc_hdr *hdr = &psc->hdr; + struct vcpu_sev_es_state *sev_es = &svm->sev_es; + struct psc_buffer *guest_psc = sev_es->ghcb_sa; __u16 idx; /* @@ -3870,14 +3867,14 @@ static void __snp_complete_one_psc(struct vcpu_svm *svm) * corresponding entries in the guest's PSC buffer and zero out the * count of in-flight PSC entries. */ - for (idx = svm->sev_es.psc_idx; svm->sev_es.psc_inflight; - svm->sev_es.psc_inflight--, idx++) { - struct psc_entry entry = READ_ONCE(entries[idx]); + for (idx = sev_es->psc.cur_idx; sev_es->psc.batch_size; + sev_es->psc.batch_size--, idx++) { + struct psc_entry entry = READ_ONCE(guest_psc->entries[idx]); - entries[idx].cur_page = entry.pagesize ? 512 : 1; + guest_psc->entries[idx].cur_page = entry.pagesize ? 512 : 1; } - hdr->cur_entry = idx; + guest_psc->hdr.cur_entry = idx; } static int snp_complete_one_psc(struct kvm_vcpu *vcpu) @@ -3898,10 +3895,8 @@ static int snp_complete_one_psc(struct kvm_vcpu *vcpu) static int snp_begin_psc(struct vcpu_svm *svm) { struct vcpu_sev_es_state *sev_es = &svm->sev_es; - struct psc_buffer *psc = sev_es->ghcb_sa; - struct psc_entry *entries = psc->entries; + struct psc_buffer *guest_psc = sev_es->ghcb_sa; struct kvm_vcpu *vcpu = &svm->vcpu; - struct psc_hdr *hdr = &psc->hdr; struct psc_entry entry_start; u16 idx, idx_start, idx_end, max_nr_entries; int npages; @@ -3928,7 +3923,7 @@ static int snp_begin_psc(struct vcpu_svm *svm) next_range: /* There should be no other PSCs in-flight at this point. */ - if (WARN_ON_ONCE(svm->sev_es.psc_inflight)) { + if (WARN_ON_ONCE(svm->sev_es.psc.batch_size)) { snp_complete_psc(svm, VMGEXIT_PSC_ERROR_GENERIC); return 1; } @@ -3938,8 +3933,8 @@ next_range: * validation, so take care to only use validated copies of values used * for things like array indexing. */ - idx_start = READ_ONCE(hdr->cur_entry); - idx_end = READ_ONCE(hdr->end_entry); + idx_start = READ_ONCE(guest_psc->hdr.cur_entry); + idx_end = READ_ONCE(guest_psc->hdr.end_entry); if (idx_end >= max_nr_entries) { snp_complete_psc(svm, VMGEXIT_PSC_ERROR_INVALID_HDR); @@ -3948,7 +3943,7 @@ next_range: /* Find the start of the next range which needs processing. */ for (idx = idx_start; idx <= idx_end; idx++) { - entry_start = READ_ONCE(entries[idx]); + entry_start = READ_ONCE(guest_psc->entries[idx]); gfn = entry_start.gfn; huge = entry_start.pagesize; @@ -3981,7 +3976,7 @@ next_range: * for READ_ONCE() as KVM doesn't consume the field, i.e. a * misbehaving guest can only break itself. */ - hdr->cur_entry++; + guest_psc->hdr.cur_entry++; } if (idx > idx_end) { @@ -3990,9 +3985,9 @@ next_range: return 1; } - svm->sev_es.psc_2m = huge; - svm->sev_es.psc_idx = idx; - svm->sev_es.psc_inflight = 1; + sev_es->psc.is_2m = huge; + sev_es->psc.cur_idx = idx; + sev_es->psc.batch_size = 1; /* * Find all subsequent PSC entries that contain adjacent GPA @@ -4000,14 +3995,14 @@ next_range: * KVM_HC_MAP_GPA_RANGE exit. */ while (++idx <= idx_end) { - struct psc_entry entry = READ_ONCE(entries[idx]); + struct psc_entry entry = READ_ONCE(guest_psc->entries[idx]); if (entry.operation != entry_start.operation || entry.gfn != entry_start.gfn + npages || entry.cur_page || !!entry.pagesize != huge) break; - svm->sev_es.psc_inflight++; + sev_es->psc.batch_size++; npages += huge ? 512 : 1; } diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index a10668d17a16a..06192bc9c1072 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -257,9 +257,11 @@ struct vcpu_sev_es_state { bool ghcb_sa_free; /* SNP Page-State-Change buffer entries currently being processed */ - u16 psc_idx; - u16 psc_inflight; - bool psc_2m; + struct { + u16 cur_idx; + u16 batch_size; + bool is_2m; + } psc; u64 ghcb_registered_gpa;