From: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx> This unit test covers: 1. CR4.LAM_SUP toggles. 2. Memory & MMIO access with supervisor mode address with LAM metadata. 3. INVLPG memory operand doesn't contain LAM meta data, if the address is non-canonical form then the INVLPG is the same as a NOP (no #GP). 4. INVPCID memory operand (descriptor pointer) could contain LAM meta data, however, the address in the descriptor should be canonical. In x86/unittests.cfg, add 2 test cases/guest conf, with and without LAM. LAM feature spec: https://cdrdv2.intel.com/v1/dl/getContent/671368, Chapter LINEAR ADDRESS MASKING (LAM) Signed-off-by: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx> Co-developed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx> Signed-off-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx> Reviewed-by: Chao Gao <chao.gao@xxxxxxxxx> --- lib/x86/processor.h | 10 ++ x86/Makefile.x86_64 | 1 + x86/lam.c | 243 ++++++++++++++++++++++++++++++++++++++++++++ x86/unittests.cfg | 10 ++ 4 files changed, 264 insertions(+) create mode 100644 x86/lam.c diff --git a/lib/x86/processor.h b/lib/x86/processor.h index ca8665b3..2d1fe3f5 100644 --- a/lib/x86/processor.h +++ b/lib/x86/processor.h @@ -8,6 +8,14 @@ #include <stdint.h> #define NONCANONICAL 0xaaaaaaaaaaaaaaaaull +#define LAM57_MASK GENMASK_ULL(62, 57) +#define LAM48_MASK GENMASK_ULL(62, 48) + +/* Set metadata with non-canonical pattern in mask bits of a linear address */ +static inline u64 set_la_non_canonical(u64 src, u64 mask) +{ + return (src & ~mask) | (NONCANONICAL & mask); +} #ifdef __x86_64__ # define R "r" @@ -120,6 +128,8 @@ #define X86_CR4_CET BIT(X86_CR4_CET_BIT) #define X86_CR4_PKS_BIT (24) #define X86_CR4_PKS BIT(X86_CR4_PKS_BIT) +#define X86_CR4_LAM_SUP_BIT (28) +#define X86_CR4_LAM_SUP BIT(X86_CR4_LAM_SUP_BIT) #define X86_EFLAGS_CF_BIT (0) #define X86_EFLAGS_CF BIT(X86_EFLAGS_CF_BIT) diff --git a/x86/Makefile.x86_64 b/x86/Makefile.x86_64 index 2771a6fa..e5db2365 100644 --- a/x86/Makefile.x86_64 +++ b/x86/Makefile.x86_64 @@ -38,6 +38,7 @@ tests += $(TEST_DIR)/rdpru.$(exe) tests += $(TEST_DIR)/pks.$(exe) tests += $(TEST_DIR)/pmu_lbr.$(exe) tests += $(TEST_DIR)/pmu_pebs.$(exe) +tests += $(TEST_DIR)/lam.$(exe) ifeq ($(CONFIG_EFI),y) tests += $(TEST_DIR)/amd_sev.$(exe) diff --git a/x86/lam.c b/x86/lam.c new file mode 100644 index 00000000..0ad16be5 --- /dev/null +++ b/x86/lam.c @@ -0,0 +1,243 @@ +/* + * Intel LAM unit test + * + * Copyright (C) 2023 Intel + * + * Author: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx> + * Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx> + * + * This work is licensed under the terms of the GNU LGPL, version 2 or + * later. + */ + +#include "libcflat.h" +#include "processor.h" +#include "desc.h" +#include "vmalloc.h" +#include "alloc_page.h" +#include "vm.h" +#include "asm/io.h" +#include "ioram.h" + +#define FLAGS_LAM_ACTIVE BIT_ULL(0) +#define FLAGS_LA57 BIT_ULL(1) + +struct invpcid_desc { + u64 pcid : 12; + u64 rsv : 52; + u64 addr; +}; + +static inline bool is_la57(void) +{ + return !!(read_cr4() & X86_CR4_LA57); +} + +static inline bool lam_sup_active(void) +{ + return !!(read_cr4() & X86_CR4_LAM_SUP); +} + +static void cr4_set_lam_sup(void *data) +{ + unsigned long cr4; + + cr4 = read_cr4(); + write_cr4_safe(cr4 | X86_CR4_LAM_SUP); +} + +static void cr4_clear_lam_sup(void *data) +{ + unsigned long cr4; + + cr4 = read_cr4(); + write_cr4_safe(cr4 & ~X86_CR4_LAM_SUP); +} + +static void test_cr4_lam_set_clear(bool has_lam) +{ + bool fault; + + fault = test_for_exception(GP_VECTOR, &cr4_set_lam_sup, NULL); + report((fault != has_lam) && (lam_sup_active() == has_lam), + "Set CR4.LAM_SUP"); + + fault = test_for_exception(GP_VECTOR, &cr4_clear_lam_sup, NULL); + report(!fault, "Clear CR4.LAM_SUP"); +} + +/* Refer to emulator.c */ +static void do_mov(void *mem) +{ + unsigned long t1, t2; + + t1 = 0x123456789abcdefull & -1ul; + asm volatile("mov %[t1], (%[mem])\n\t" + "mov (%[mem]), %[t2]" + : [t2]"=r"(t2) + : [t1]"r"(t1), [mem]"r"(mem) + : "memory"); + report(t1 == t2, "Mov result check"); +} + +static u64 test_ptr(u64 arg1, u64 arg2, u64 arg3, u64 arg4) +{ + bool lam_active = !!(arg1 & FLAGS_LAM_ACTIVE); + u64 lam_mask = arg2; + u64 *ptr = (u64 *)arg3; + bool is_mmio = !!arg4; + bool fault; + + fault = test_for_exception(GP_VECTOR, do_mov, ptr); + report(!fault, "Test untagged addr (%s)", is_mmio ? "MMIO" : "Memory"); + + ptr = (u64 *)set_la_non_canonical((u64)ptr, lam_mask); + fault = test_for_exception(GP_VECTOR, do_mov, ptr); + report(fault != lam_active,"Test tagged addr (%s)", + is_mmio ? "MMIO" : "Memory"); + + return 0; +} + +static void do_invlpg(void *mem) +{ + invlpg(mem); +} + +static void do_invlpg_fep(void *mem) +{ + asm volatile(KVM_FEP "invlpg (%0)" ::"r" (mem) : "memory"); +} + +/* invlpg with tagged address is same as NOP, no #GP expected. */ +static void test_invlpg(u64 lam_mask, void *va, bool fep) +{ + bool fault; + u64 *ptr; + + ptr = (u64 *)set_la_non_canonical((u64)va, lam_mask); + if (fep) + fault = test_for_exception(GP_VECTOR, do_invlpg_fep, ptr); + else + fault = test_for_exception(GP_VECTOR, do_invlpg, ptr); + + report(!fault, "%sINVLPG with tagged addr", fep ? "fep: " : ""); +} + +static void do_invpcid(void *desc) +{ + struct invpcid_desc *desc_ptr = (struct invpcid_desc *)desc; + + asm volatile("invpcid %0, %1" : + : "m" (*desc_ptr), "r" (0UL) + : "memory"); +} + +/* LAM doesn't apply to the linear address in the descriptor of invpcid */ +static void test_invpcid(u64 flags, u64 lam_mask, void *data) +{ + /* + * Reuse the memory address for the descriptor since stack memory + * address in KUT doesn't follow the kernel address space partitions. + */ + struct invpcid_desc *desc_ptr = (struct invpcid_desc *)data; + bool lam_active = !!(flags & FLAGS_LAM_ACTIVE); + bool fault; + + if (!this_cpu_has(X86_FEATURE_PCID) || + !this_cpu_has(X86_FEATURE_INVPCID)) { + report_skip("INVPCID not supported"); + return; + } + + memset(desc_ptr, 0, sizeof(struct invpcid_desc)); + desc_ptr->addr = (u64)data; + + fault = test_for_exception(GP_VECTOR, do_invpcid, desc_ptr); + report(!fault, "INVPCID: untagged pointer + untagged addr"); + + desc_ptr->addr = set_la_non_canonical(desc_ptr->addr, lam_mask); + fault = test_for_exception(GP_VECTOR, do_invpcid, desc_ptr); + report(fault, "INVPCID: untagged pointer + tagged addr"); + + desc_ptr = (struct invpcid_desc *)set_la_non_canonical((u64)desc_ptr, + lam_mask); + fault = test_for_exception(GP_VECTOR, do_invpcid, desc_ptr); + report(fault, "INVPCID: tagged pointer + tagged addr"); + + desc_ptr = (struct invpcid_desc *)data; + desc_ptr->addr = (u64)data; + desc_ptr = (struct invpcid_desc *)set_la_non_canonical((u64)desc_ptr, + lam_mask); + fault = test_for_exception(GP_VECTOR, do_invpcid, desc_ptr); + report(fault != lam_active, "INVPCID: tagged pointer + untagged addr"); +} + +static void test_lam_sup(bool has_lam, bool fep_available) +{ + void *vaddr, *vaddr_mmio; + phys_addr_t paddr; + u64 lam_mask = LAM48_MASK; + u64 flags = 0; + bool fault; + + /* + * KUT initializes vfree_top to 0 for X86_64, and each virtual address + * allocation decreases the size from vfree_top. It's guaranteed that + * the return value of alloc_vpage() is considered as kernel mode + * address and canonical since only a small mount virtual address range + * is allocated in this test. + */ + vaddr = alloc_vpage(); + vaddr_mmio = alloc_vpage(); + paddr = virt_to_phys(alloc_page()); + install_page(current_page_table(), paddr, vaddr); + install_page(current_page_table(), IORAM_BASE_PHYS, vaddr_mmio); + + test_cr4_lam_set_clear(has_lam); + + /* Set for the following LAM_SUP tests */ + if (has_lam) { + fault = test_for_exception(GP_VECTOR, &cr4_set_lam_sup, NULL); + report(!fault && lam_sup_active(), "Set CR4.LAM_SUP"); + } + + if (lam_sup_active()) + flags |= FLAGS_LAM_ACTIVE; + + if (is_la57()) { + flags |= FLAGS_LA57; + lam_mask = LAM57_MASK; + } + + /* Test for normal memory */ + test_ptr(flags, lam_mask, (u64)vaddr, false); + /* Test for MMIO to trigger instruction emulation */ + test_ptr(flags, lam_mask, (u64)vaddr_mmio, true); + test_invpcid(flags, lam_mask, vaddr); + test_invlpg(lam_mask, vaddr, false); + if (fep_available) + test_invlpg(lam_mask, vaddr, true); +} + +int main(int ac, char **av) +{ + bool has_lam; + bool fep_available = is_fep_available(); + + setup_vm(); + + has_lam = this_cpu_has(X86_FEATURE_LAM); + if (!has_lam) + report_info("This CPU doesn't support LAM feature\n"); + else + report_info("This CPU supports LAM feature\n"); + + if (!fep_available) + report_skip("Skipping tests the forced emulation, " + "use kvm.force_emulation_prefix=1 to enable\n"); + + test_lam_sup(has_lam, fep_available); + + return report_summary(); +} diff --git a/x86/unittests.cfg b/x86/unittests.cfg index 3fe59449..224df45b 100644 --- a/x86/unittests.cfg +++ b/x86/unittests.cfg @@ -491,3 +491,13 @@ file = cet.flat arch = x86_64 smp = 2 extra_params = -enable-kvm -m 2048 -cpu host + +[intel-lam] +file = lam.flat +arch = x86_64 +extra_params = -enable-kvm -cpu host + +[intel-no-lam] +file = lam.flat +arch = x86_64 +extra_params = -enable-kvm -cpu host,-lam -- 2.25.1
