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 <thomas.lendacky@amd.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260501202250.2115252-13-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <20260529183549.1104619-13-pbonzini@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 1982d13e71d9e1955eb013be5dc683a976179c66..9f6543cebedf55d3737020ff1278a3b24432e83a 100644 (file)
--- 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 a10668d17a16a0e32714c8c81feaf3eaea4966ba..06192bc9c1072f3e9a9e8c7a1ba5cf7e439dffdb 100644 (file)
--- 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;