From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id AD344346784; Sat, 16 May 2026 18:31:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778956270; cv=none; b=c4Otk7HiMEiA+OheYbrxlyVdyaMRMRM/cpeJEy2mp9EusU/IEpc/6oFB3tTpRjbV2CtIGAmGQHkCIJGboO8rR5Ig8tvkrQ0jE3z+uXBUZOQMS/pVPmQBwOyIrJd+GbR3qKizPxni0/UKlhDHJ1978x4M5tvP+Rqm0Bh0IaG6aYk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778956270; c=relaxed/simple; bh=jADMEVZuXP3pAMbKzFIdmO4l26Z49yvuX6i+PGRaGSI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JMBT8s4qBsuEHhwb1cuLOPndCcBATJ2LtnsoBuKbPd1IzUsQowbKJQfCgCrPtEwCVE0LS/yXSCIpIoee0G+ynPFDVRdinW9V+ZfrsME0dqCLnJqGCGSI3NWwhTFWWiL3GI6s7tUgjhh2lckaZm2k2gTzIkNrrz9Em6olr3Pw9aI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=EMtBQNSd; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="EMtBQNSd" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 7E1C91CDD; Sat, 16 May 2026 11:31:01 -0700 (PDT) Received: from workstation-e142269.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 134633F85F; Sat, 16 May 2026 11:31:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1778956266; bh=jADMEVZuXP3pAMbKzFIdmO4l26Z49yvuX6i+PGRaGSI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=EMtBQNSdsfY93wcLqMuI5+b453PA5kzcOT/rTsqInDh8uabl8rFIATtsowQL62NI9 Wtvcip2D30av12+kf64gPKTyQj/414nurusUCSeb+f0FncU8zzZlwxuyvULAkci6wm C73C1WaSK7A+4LiJnP58PJMMZS9Usa098a5pEUX4= From: Wei-Lin Chang To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Cc: Paolo Bonzini , Shuah Khan , Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Itaru Kitayama , Wei-Lin Chang Subject: [PATCH v3 6/9] KVM: arm64: selftests: shadow_stage2: Allocate L2 stack from dedicated pool Date: Sat, 16 May 2026 19:30:00 +0100 Message-ID: <20260516183003.799058-7-weilin.chang@arm.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20260516183003.799058-1-weilin.chang@arm.com> References: <20260516183003.799058-1-weilin.chang@arm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Instead of using L1's stack, create a simple page allocator and use that to allocate L2 stack. The allocator will also be used later on when the stage-2 page table generator builds stage-2 mappings for the nested guest (L2). Signed-off-by: Wei-Lin Chang --- .../selftests/kvm/arm64/shadow_stage2.c | 20 ++++++++--- .../selftests/kvm/include/arm64/nested.h | 9 +++++ .../testing/selftests/kvm/lib/arm64/nested.c | 33 +++++++++++++++++++ 3 files changed, 58 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/kvm/arm64/shadow_stage2.c b/tools/testing/selftests/kvm/arm64/shadow_stage2.c index cf76a2b0582d..1ad510a38654 100644 --- a/tools/testing/selftests/kvm/arm64/shadow_stage2.c +++ b/tools/testing/selftests/kvm/arm64/shadow_stage2.c @@ -9,12 +9,16 @@ #include "ucall.h" #define XLATE2GPA (0xABCD) -#define L2STACKSZ (0x100) #define L2SUCCESS (0x0) #define L2FAILED (0x1) #define L2SYNC (0x2) +/* Used for L2 stack and guest S2 page tables. */ +#define L2_PAGE_POOL_ADDR (0x80000000) +#define L2_PAGE_POOL_NPAGES (512) +#define L2_PAGE_POOL_MEMSLOT (0x2) + /* * TPIDR_EL2 is used to store vcpu id, so save and restore it. */ @@ -48,14 +52,18 @@ static void guest_code(void) struct hyp_data hyp_data; int ret, i = 0; gpa_t l2_pc, l2_stack_top; - /* force 16-byte alignment for the stack pointer */ - u8 l2_stack[L2STACKSZ] __attribute__((aligned(16))); + struct page_pool pp; GUEST_ASSERT_EQ(get_current_el(), 2); GUEST_PRINTF("vEL2 entry\n"); + pp.start = L2_PAGE_POOL_ADDR; + pp.npages = L2_PAGE_POOL_NPAGES; + pp.current = L2_PAGE_POOL_ADDR; + pp.page_size = get_page_size(); + + l2_stack_top = alloc_page(&pp) + pp.page_size; l2_pc = ucall_translate_to_gpa(l2_guest_code); - l2_stack_top = ucall_translate_to_gpa(&l2_stack[L2STACKSZ]); init_vcpu(&vcpu, l2_pc, l2_stack_top); prepare_hyp(); @@ -96,6 +104,10 @@ int main(void) vcpu = aarch64_vcpu_add(vm, 0, &init, guest_code); kvm_arch_vm_finalize_vcpus(vm); + vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS, + L2_PAGE_POOL_ADDR, L2_PAGE_POOL_MEMSLOT, + L2_PAGE_POOL_NPAGES, 0); + while (true) { vcpu_run(vcpu); diff --git a/tools/testing/selftests/kvm/include/arm64/nested.h b/tools/testing/selftests/kvm/include/arm64/nested.h index c10ef4a85be7..8e7d7738b381 100644 --- a/tools/testing/selftests/kvm/include/arm64/nested.h +++ b/tools/testing/selftests/kvm/include/arm64/nested.h @@ -46,6 +46,15 @@ struct hyp_data { struct cpu_context hyp_context; }; +struct page_pool { + gpa_t start; + gpa_t current; + size_t npages; + size_t page_size; +}; + +size_t get_page_size(void); +gpa_t alloc_page(struct page_pool *pp); void prepare_hyp(void); void init_vcpu(struct vcpu *vcpu, gpa_t l2_pc, gpa_t l2_stack_top); int run_l2(struct vcpu *vcpu, struct hyp_data *hyp_data); diff --git a/tools/testing/selftests/kvm/lib/arm64/nested.c b/tools/testing/selftests/kvm/lib/arm64/nested.c index f6c24beb01d0..7f47e340f00d 100644 --- a/tools/testing/selftests/kvm/lib/arm64/nested.c +++ b/tools/testing/selftests/kvm/lib/arm64/nested.c @@ -7,6 +7,39 @@ #include "processor.h" #include "test_util.h" #include +#include + +size_t get_page_size(void) +{ + u64 tcr_el1 = read_sysreg(tcr_el1); + u64 tg0 = SYS_FIELD_GET(TCR_EL1, TG0, tcr_el1); + + switch (tg0) { + case TCR_EL1_TG0_4K: + return SZ_4K; + case TCR_EL1_TG0_16K: + return SZ_16K; + case TCR_EL1_TG0_64K: + return SZ_64K; + default: + GUEST_FAIL("Unexpected tg0 value!\n"); + return 0; + } +} + +gpa_t alloc_page(struct page_pool *pp) +{ + gpa_t page = pp->current; + + pp->current += pp->page_size; + + if ((pp->current - pp->start) / pp->page_size <= pp->npages) { + return page; + } else { + GUEST_FAIL("%s failed!\n", __func__); + return 0; + } +} void prepare_hyp(void) { -- 2.43.0