[kvm-unit-tests,v7,2/2] x86: nvmx: test max atomic switch MSRs

Message ID	20190925011821.24523-2-marcorr@google.com (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=acwS=XU=vger.kernel.org=kvm-owner@kernel.org> Date: Tue, 24 Sep 2019 18:18:21 -0700 In-Reply-To: <20190925011821.24523-1-marcorr@google.com> Message-Id: <20190925011821.24523-2-marcorr@google.com> Mime-Version: 1.0 References: <20190925011821.24523-1-marcorr@google.com> Subject: [kvm-unit-tests PATCH v7 2/2] x86: nvmx: test max atomic switch MSRs From: Marc Orr <marcorr@google.com> To: kvm@vger.kernel.org, jmattson@google.com, pshier@google.com, sean.j.christopherson@intel.com, krish.sadhukhan@oracle.com, pbonzini@redhat.com, rkrcmar@redhat.com, dinechin@redhat.com Cc: Marc Orr <marcorr@google.com> Content-Type: text/plain; charset="UTF-8" Sender: kvm-owner@vger.kernel.org Precedence: bulk
Series	[kvm-unit-tests,v7,1/2] x86: nvmx: fix bug in __enter_guest() \| expand [kvm-unit-tests,v7,1/2] x86: nvmx: fix bug in __enter_guest() [kvm-unit-tests,v7,2/2] x86: nvmx: test max atomic switch MSRs

diff --git a/lib/alloc_page.c b/lib/alloc_page.c index 97d13395ff08..ed236389537e 100644 --- a/lib/alloc_page.c +++ b/lib/alloc_page.c @@ -53,6 +53,11 @@ void free_pages(void *mem, unsigned long size) spin_unlock(&lock); } +void free_pages_by_order(void *mem, unsigned long order) +{ + free_pages(mem, 1ul << (order + PAGE_SHIFT)); +} + void *alloc_page() { void *p; diff --git a/lib/alloc_page.h b/lib/alloc_page.h index 5cdfec57a0a8..739a91def979 100644 --- a/lib/alloc_page.h +++ b/lib/alloc_page.h @@ -14,5 +14,6 @@ void *alloc_page(void); void *alloc_pages(unsigned long order); void free_page(void *page); void free_pages(void *mem, unsigned long size); +void free_pages_by_order(void *mem, unsigned long order); #endif diff --git a/x86/unittests.cfg b/x86/unittests.cfg index 694ee3d42f3a..05122cf91ea1 100644 --- a/x86/unittests.cfg +++ b/x86/unittests.cfg @@ -227,7 +227,7 @@ extra_params = -cpu qemu64,+umip [vmx] file = vmx.flat -extra_params = -cpu host,+vmx -append "-exit_monitor_from_l2_test -ept_access* -vmx_smp* -vmx_vmcs_shadow_test" +extra_params = -cpu host,+vmx -append "-exit_monitor_from_l2_test -ept_access* -vmx_smp* -vmx_vmcs_shadow_test -atomic_switch_overflow_msrs_test" arch = x86_64 groups = vmx diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c index f035f24a771a..6eb18d8fd3e4 100644 --- a/x86/vmx_tests.c +++ b/x86/vmx_tests.c @@ -8570,6 +8570,127 @@ static int invalid_msr_entry_failure(struct vmentry_failure *failure) return VMX_TEST_VMEXIT; } +/* + * The max number of MSRs in an atomic switch MSR list is: + * (111B + 1) * 512 = 4096 + * + * Each list entry consumes: + * 4-byte MSR index + 4 bytes reserved + 8-byte data = 16 bytes + * + * Allocate 128 kB to cover max_msr_list_size (i.e., 64 kB) and then some. + */ +static const u32 msr_list_page_order = 5; + +static void populate_msr_list(struct vmx_msr_entry *msr_list, + size_t byte_capacity, int count) +{ + int i; + + for (i = 0; i < count; i++) { + msr_list[i].index = MSR_IA32_TSC; + msr_list[i].reserved = 0; + msr_list[i].value = 0x1234567890abcdef; + } + + memset(msr_list + count, 0xff, + byte_capacity - count * sizeof(*msr_list)); +} + +static int max_msr_list_size(void) +{ + u32 vmx_misc = rdmsr(MSR_IA32_VMX_MISC); + u32 factor = ((vmx_misc & GENMASK(27, 25)) >> 25) + 1; + + return factor * 512; +} + +static void atomic_switch_msrs_test(int count) +{ + int max_allowed = max_msr_list_size(); + int byte_capacity = 1ul << (msr_list_page_order + PAGE_SHIFT); + /* KVM signals VM-Abort if an exit MSR list exceeds the max size. */ + int exit_count = MIN(count, max_allowed); + + /* + * Check for the IA32_TSC MSR, + * available with the "TSC flag" and used to populate the MSR lists. + */ + if (!(cpuid(1).d & (1 << 4))) { + report_skip(__func__); + return; + } + + /* Set L2 guest. */ + test_set_guest(v2_null_test_guest); + + /* Setup atomic MSR switch lists. */ + entry_msr_load = alloc_pages(msr_list_page_order); + exit_msr_load = alloc_pages(msr_list_page_order); + exit_msr_store = alloc_pages(msr_list_page_order); + + vmcs_write(ENTER_MSR_LD_ADDR, (u64)entry_msr_load); + vmcs_write(EXIT_MSR_LD_ADDR, (u64)exit_msr_load); + vmcs_write(EXIT_MSR_ST_ADDR, (u64)exit_msr_store); + + /* + * VM-Enter should succeed up to the max number of MSRs per list, and + * should not consume junk beyond the last entry. + */ + populate_msr_list(entry_msr_load, byte_capacity, count); + populate_msr_list(exit_msr_load, byte_capacity, exit_count); + populate_msr_list(exit_msr_store, byte_capacity, exit_count); + + vmcs_write(ENT_MSR_LD_CNT, count); + vmcs_write(EXI_MSR_LD_CNT, exit_count); + vmcs_write(EXI_MSR_ST_CNT, exit_count); + + if (count <= max_allowed) { + /* + * enter_guest() verifies that VM-enter succeeds. After the + * test completes, the test harness (see test_run() in vmx.c) + * verifies that the VM-enter completes by reaching the end of + * v2_null_test_guest(). + */ + enter_guest(); + } else { + u32 exit_reason; + u32 exit_reason_want; + u32 exit_qual; + + enter_guest_with_invalid_guest_state(); + + exit_reason = vmcs_read(EXI_REASON); + exit_reason_want = VMX_FAIL_MSR | VMX_ENTRY_FAILURE; + report("exit_reason %u, expected %u.", + exit_reason == exit_reason_want, exit_reason, + exit_reason_want); + + exit_qual = vmcs_read(EXI_QUALIFICATION); + report("exit_qual %u, expected %u.", + exit_qual == max_allowed + 1, exit_qual, + max_allowed + 1); + + /* Enter the guest (with valid counts) to set guest_finished. */ + vmcs_write(ENT_MSR_LD_CNT, 0); + vmcs_write(EXI_MSR_LD_CNT, 0); + vmcs_write(EXI_MSR_ST_CNT, 0); + enter_guest(); + } + + free_pages_by_order(entry_msr_load, msr_list_page_order); + free_pages_by_order(exit_msr_load, msr_list_page_order); + free_pages_by_order(exit_msr_store, msr_list_page_order); +} + +static void atomic_switch_max_msrs_test(void) +{ + atomic_switch_msrs_test(max_msr_list_size()); +} + +static void atomic_switch_overflow_msrs_test(void) +{ + atomic_switch_msrs_test(max_msr_list_size() + 1); +} #define TEST(name) { #name, .v2 = name } @@ -8660,5 +8781,8 @@ struct vmx_test vmx_tests[] = { TEST(ept_access_test_paddr_read_execute_ad_enabled), TEST(ept_access_test_paddr_not_present_page_fault), TEST(ept_access_test_force_2m_page), + /* Atomic MSR switch tests. */ + TEST(atomic_switch_max_msrs_test), + TEST(atomic_switch_overflow_msrs_test), { NULL, NULL, NULL, NULL, NULL, {0} }, };

[kvm-unit-tests,v7,2/2] x86: nvmx: test max atomic switch MSRs

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