From nobody Sun Oct 5 21:49:27 2025 Received: from mail-pj1-f73.google.com (mail-pj1-f73.google.com [209.85.216.73]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8009A2D8773 for ; Tue, 29 Jul 2025 22:56:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.216.73 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753829775; cv=none; b=Q1CqK5DsAMaKpTvdEr2ZKRBs+N4yQgcepI55JPsF5YTwOnDV8Mo2jZL2uGDU3lqN3FQM74Spw0CIbYD8o9WCdvsNClJ9FJXTOJnP/LyzsHIJLDOPFgWjC+JI7Pg4o9H74KlvHIo6kgIR3cETxSYcDtPwiCLB9W7Zj4b+azK19vY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753829775; c=relaxed/simple; bh=iqeIz6zYpzKsdgmtTVnjWowKoLeDnq0bjWKhZ9mqs7E=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=KFwzpvbzQARFUNUwjJSqIAWowXq+49Wqoui0uy5bhG1bCkziJAKx86bK+J1LRRzvBPUU9CsZsFCowqc6zka8BeFnlXpujeFGAEWM/pwd38LPeLB+gkAPm1CLPs+i00uueRLfzZR7PPzyW71KZ+J345mWj/FVGCG00cvGMMgC/hs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=KBeHc1KV; arc=none smtp.client-ip=209.85.216.73 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--seanjc.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="KBeHc1KV" Received: by mail-pj1-f73.google.com with SMTP id 98e67ed59e1d1-31218e2d5b0so10280273a91.2 for ; Tue, 29 Jul 2025 15:56:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1753829773; x=1754434573; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:from:to:cc:subject:date:message-id:reply-to; bh=EorjiQ424BTohGrqf8DNWx/AmqFoym4CNGeVIARROHM=; b=KBeHc1KVJwXSKbp9O+czZQIFCBP4hHC9Sl3G6K5juUs8b+3jEYqaJvhwjUq7gL3vjp JwwJz0j9Wo2qFPkGSf+wq5vEVhiIs92xjffMoe1ar9NcCY3BItYEdKrviEU/rLST5Yeq h9v4UYhaaxQ1Nkh/kTuKtfu5LZD9ZbPRe+Nc+fpEvMxaPxH/70lO9dRGm5gDruzOFWc8 /tGDGwd4DTFvt0Pg9NNvNiIrSAf43jp5AgnwQerklyYdHi4GLfo3mJB0B2YKzmEaiLc5 rS51waiMHl/llJ8pt+5gAjwJo1NC8hrU5GfLdcffomE4GtDdldFY37m9vuTalSNs9JrE 62Gw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1753829773; x=1754434573; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:reply-to:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=EorjiQ424BTohGrqf8DNWx/AmqFoym4CNGeVIARROHM=; b=YGmbZWvbq2aR/eMI+i7C+A7NE8vufbhN/9CPzcfzgpqEsqbR2/bXMVEhdpWUIBIYb/ vdOxWn04+ZxfcswdBEUAS7elvieHibFfp+OL1xB7yI7HPhC9da61Q5LO15xFjPWB/pD9 bohbca5kV4usQiD0/dkxJ42Bv6RAeoStYbeJK3cvQiwaZQsCQNcmKCH86qBrgI1+3J4F zDK3S/uwvWBzQpdEua8r14e8TYVOZUSVJF2jB4zBN8TvSPkpjJusbS2Rsx+LZvpFdQae 3ugNdYzQuRlCBuCb1GJuCi8RK3sYDqnpPRcep3pI5mV3M72ZWrIF1A1Z6yzAVpfLTL6S dIpA== X-Forwarded-Encrypted: i=1; AJvYcCUSO7vb5svr0quYuMZlIwH7wf24dB2M5k1+S7eVSyKP5sRxfC0V0Yyc5m/DH9NGT6G7vLCOfj9U+eig4fU=@vger.kernel.org X-Gm-Message-State: AOJu0Yyp55dnBv9DCFGmIl2BJ8UMqoS+QZXIc2cF9+WlOnMJVKrgqUlE a/FH3Qbj0o+mZtNtaFvdWgsEwsc7ot3pQGTJSd2scSbMt7F+Bgx3WJscsjedKMEswaCeLz9cNpa ZUa5ewQ== X-Google-Smtp-Source: AGHT+IHB9c2363ufbpvtr+JBuwDrzcLhfsH2Xd3qM0cBsmlln2L/OVyYyxyGr5yAT46jm6mjT2DN+GL7x3k= X-Received: from pjee15.prod.google.com ([2002:a17:90b:578f:b0:31e:fe0d:f464]) (user=seanjc job=prod-delivery.src-stubby-dispatcher) by 2002:a17:90b:288b:b0:311:df4b:4b94 with SMTP id 98e67ed59e1d1-31f5ddb7ea8mr1459342a91.4.1753829772835; Tue, 29 Jul 2025 15:56:12 -0700 (PDT) Reply-To: Sean Christopherson Date: Tue, 29 Jul 2025 15:54:55 -0700 In-Reply-To: <20250729225455.670324-1-seanjc@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250729225455.670324-1-seanjc@google.com> X-Mailer: git-send-email 2.50.1.552.g942d659e1b-goog Message-ID: <20250729225455.670324-25-seanjc@google.com> Subject: [PATCH v17 24/24] KVM: selftests: Add guest_memfd testcase to fault-in on !mmap()'d memory From: Sean Christopherson To: Paolo Bonzini , Marc Zyngier , Oliver Upton , Sean Christopherson Cc: kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, Ira Weiny , Gavin Shan , Shivank Garg , Vlastimil Babka , Xiaoyao Li , David Hildenbrand , Fuad Tabba , Ackerley Tng , Tao Chan , James Houghton Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Add a guest_memfd testcase to verify that a vCPU can fault-in guest_memfd memory that supports mmap(), but that is not currently mapped into host userspace and/or has a userspace address (in the memslot) that points at something other than the target guest_memfd range. Mapping guest_memfd memory into the guest is supposed to operate completely independently from any userspace mappings. Signed-off-by: Sean Christopherson --- .../testing/selftests/kvm/guest_memfd_test.c | 64 +++++++++++++++++++ 1 file changed, 64 insertions(+) diff --git a/tools/testing/selftests/kvm/guest_memfd_test.c b/tools/testing= /selftests/kvm/guest_memfd_test.c index 088053d5f0f5..b86bf89a71e0 100644 --- a/tools/testing/selftests/kvm/guest_memfd_test.c +++ b/tools/testing/selftests/kvm/guest_memfd_test.c @@ -13,6 +13,7 @@ =20 #include #include +#include #include #include #include @@ -21,6 +22,7 @@ =20 #include "kvm_util.h" #include "test_util.h" +#include "ucall_common.h" =20 static void test_file_read_write(int fd) { @@ -298,6 +300,66 @@ static void test_guest_memfd(unsigned long vm_type) kvm_vm_free(vm); } =20 +static void guest_code(uint8_t *mem, uint64_t size) +{ + size_t i; + + for (i =3D 0; i < size; i++) + __GUEST_ASSERT(mem[i] =3D=3D 0xaa, + "Guest expected 0xaa at offset %lu, got 0x%x", i, mem[i]); + + memset(mem, 0xff, size); + GUEST_DONE(); +} + +static void test_guest_memfd_guest(void) +{ + /* + * Skip the first 4gb and slot0. slot0 maps <1gb and is used to back + * the guest's code, stack, and page tables, and low memory contains + * the PCI hole and other MMIO regions that need to be avoided. + */ + const uint64_t gpa =3D SZ_4G; + const int slot =3D 1; + + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + uint8_t *mem; + size_t size; + int fd, i; + + if (!kvm_has_cap(KVM_CAP_GUEST_MEMFD_MMAP)) + return; + + vm =3D __vm_create_shape_with_one_vcpu(VM_SHAPE_DEFAULT, &vcpu, 1, guest_= code); + + TEST_ASSERT(vm_check_cap(vm, KVM_CAP_GUEST_MEMFD_MMAP), + "Default VM type should always support guest_memfd mmap()"); + + size =3D vm->page_size; + fd =3D vm_create_guest_memfd(vm, size, GUEST_MEMFD_FLAG_MMAP); + vm_set_user_memory_region2(vm, slot, KVM_MEM_GUEST_MEMFD, gpa, size, NULL= , fd, 0); + + mem =3D mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + TEST_ASSERT(mem !=3D MAP_FAILED, "mmap() on guest_memfd failed"); + memset(mem, 0xaa, size); + munmap(mem, size); + + virt_pg_map(vm, gpa, gpa); + vcpu_args_set(vcpu, 2, gpa, size); + vcpu_run(vcpu); + + TEST_ASSERT_EQ(get_ucall(vcpu, NULL), UCALL_DONE); + + mem =3D mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); + TEST_ASSERT(mem !=3D MAP_FAILED, "mmap() on guest_memfd failed"); + for (i =3D 0; i < size; i++) + TEST_ASSERT_EQ(mem[i], 0xff); + + close(fd); + kvm_vm_free(vm); +} + int main(int argc, char *argv[]) { unsigned long vm_types, vm_type; @@ -314,4 +376,6 @@ int main(int argc, char *argv[]) =20 for_each_set_bit(vm_type, &vm_types, BITS_PER_TYPE(vm_types)) test_guest_memfd(vm_type); + + test_guest_memfd_guest(); } --=20 2.50.1.552.g942d659e1b-goog