linux-kernel - [RFC V1 PATCH 4/5] selftests: kvm: priv_memfd

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Message-Id: <20220408210545.3915712-5-vannapurve@google.com>
Date:   Fri,  8 Apr 2022 21:05:44 +0000
From:   Vishal Annapurve <vannapurve@...gle.com>
To:     x86@...nel.org, kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-kselftest@...r.kernel.org
Cc:     pbonzini@...hat.com, vkuznets@...hat.com, wanpengli@...cent.com,
        jmattson@...gle.com, joro@...tes.org, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
        hpa@...or.com, shauh@...nel.org, yang.zhong@...el.com,
        drjones@...hat.com, ricarkol@...gle.com, aaronlewis@...gle.com,
        wei.w.wang@...el.com, kirill.shutemov@...ux.intel.com,
        corbet@....net, hughd@...gle.com, jlayton@...nel.org,
        bfields@...ldses.org, akpm@...ux-foundation.org,
        chao.p.peng@...ux.intel.com, yu.c.zhang@...ux.intel.com,
        jun.nakajima@...el.com, dave.hansen@...el.com,
        michael.roth@....com, qperret@...gle.com, steven.price@....com,
        ak@...ux.intel.com, david@...hat.com, luto@...nel.org,
        vbabka@...e.cz, marcorr@...gle.com, erdemaktas@...gle.com,
        pgonda@...gle.com, seanjc@...gle.com, diviness@...gle.com,
        Vishal Annapurve <vannapurve@...gle.com>
Subject: [RFC V1 PATCH 4/5] selftests: kvm: priv_memfd_test: Add support for
 memory conversion

Add handling of explicit private/shared memory conversion using
KVM_HC_MAP_GPA_RANGE and implicit memory conversion by handling
KVM_EXIT_MEMORY_ERROR.

Signed-off-by: Vishal Annapurve <vannapurve@...gle.com>
---
 tools/testing/selftests/kvm/priv_memfd_test.c | 87 +++++++++++++++++++
 1 file changed, 87 insertions(+)

diff --git a/tools/testing/selftests/kvm/priv_memfd_test.c b/tools/testing/selftests/kvm/priv_memfd_test.c
index 11ccdb853a84..0e6c19501f27 100644
--- a/tools/testing/selftests/kvm/priv_memfd_test.c
+++ b/tools/testing/selftests/kvm/priv_memfd_test.c
@@ -129,6 +129,83 @@ static struct test_run_helper priv_memfd_testsuite[] = {
 	},
 };
 
+static void handle_vm_exit_hypercall(struct kvm_run *run,
+	uint32_t test_id)
+{
+	uint64_t gpa, npages, attrs;
+	int priv_memfd =
+		priv_memfd_testsuite[test_id].priv_memfd;
+	int ret;
+	int fallocate_mode;
+
+	if (run->hypercall.nr != KVM_HC_MAP_GPA_RANGE) {
+		TEST_FAIL("Unhandled Hypercall %lld\n",
+					run->hypercall.nr);
+	}
+
+	gpa = run->hypercall.args[0];
+	npages = run->hypercall.args[1];
+	attrs = run->hypercall.args[2];
+
+	if ((gpa >= TEST_MEM_GPA) && ((gpa +
+		(npages << MIN_PAGE_SHIFT)) <= TEST_MEM_END)) {
+		TEST_FAIL("Unhandled gpa 0x%lx npages %ld\n",
+			gpa, npages);
+	}
+
+	if (attrs & KVM_MAP_GPA_RANGE_ENCRYPTED)
+		fallocate_mode = 0;
+	else {
+		fallocate_mode = (FALLOC_FL_PUNCH_HOLE |
+			FALLOC_FL_KEEP_SIZE);
+	}
+	pr_info("Converting off 0x%lx pages 0x%lx to %s\n",
+		(gpa - TEST_MEM_GPA), npages,
+		fallocate_mode ?
+			"shared" : "private");
+	ret = fallocate(priv_memfd, fallocate_mode,
+		(gpa - TEST_MEM_GPA),
+		npages << MIN_PAGE_SHIFT);
+	TEST_ASSERT(ret != -1,
+		"fallocate failed in hc handling");
+	run->hypercall.ret = 0;
+}
+
+static void handle_vm_exit_memory_error(struct kvm_run *run,
+	uint32_t test_id)
+{
+	uint64_t gpa, size, flags;
+	int ret;
+	int priv_memfd =
+		priv_memfd_testsuite[test_id].priv_memfd;
+	int fallocate_mode;
+
+	gpa = run->memory.gpa;
+	size = run->memory.size;
+	flags = run->memory.flags;
+
+	if ((gpa < TEST_MEM_GPA) || ((gpa + size)
+					> TEST_MEM_END)) {
+		TEST_FAIL("Unhandled gpa 0x%lx size 0x%lx\n",
+			gpa, size);
+	}
+
+	if (flags & KVM_MEMORY_EXIT_FLAG_PRIVATE)
+		fallocate_mode = 0;
+	else {
+		fallocate_mode = (FALLOC_FL_PUNCH_HOLE |
+				FALLOC_FL_KEEP_SIZE);
+	}
+	pr_info("Converting off 0x%lx size 0x%lx to %s\n",
+		(gpa - TEST_MEM_GPA), size,
+		fallocate_mode ?
+			"shared" : "private");
+	ret = fallocate(priv_memfd, fallocate_mode,
+		(gpa - TEST_MEM_GPA), size);
+	TEST_ASSERT(ret != -1,
+		"fallocate failed in memory error handling");
+}
+
 static void vcpu_work(struct kvm_vm *vm, uint32_t test_id)
 {
 	struct kvm_run *run;
@@ -155,6 +232,16 @@ static void vcpu_work(struct kvm_vm *vm, uint32_t test_id)
 			continue;
 		}
 
+		if (run->exit_reason == KVM_EXIT_HYPERCALL) {
+			handle_vm_exit_hypercall(run, test_id);
+			continue;
+		}
+
+		if (run->exit_reason == KVM_EXIT_MEMORY_ERROR) {
+			handle_vm_exit_memory_error(run, test_id);
+			continue;
+		}
+
 		TEST_FAIL("Unhandled VCPU exit reason %d\n", run->exit_reason);
 		break;
 	}
-- 
2.35.1.1178.g4f1659d476-goog