From 164a9f712fa53e4c92b2a435bb071a5be0c31dbc Mon Sep 17 00:00:00 2001 From: Jason Andryuk Date: Thu, 10 Apr 2025 15:31:05 -0400 Subject: [PATCH 1/5] x86/xen: Fix __xen_hypercall_setfunc() Hypercall detection is failing with xen_hypercall_intel() chosen even on an AMD processor. Looking at the disassembly, the call to xen_get_vendor() was removed. The check for boot_cpu_has(X86_FEATURE_CPUID) was used as a proxy for the x86_vendor having been set. When CONFIG_X86_REQUIRED_FEATURE_CPUID=y (the default value), DCE eliminates the call to xen_get_vendor(). An uninitialized value 0 means X86_VENDOR_INTEL, so the Intel function is always returned. Remove the if and always call xen_get_vendor() to avoid this issue. Fixes: 3d37d9396eb3 ("x86/cpufeatures: Add {REQUIRED,DISABLED} feature configs") Suggested-by: Juergen Gross Signed-off-by: Jason Andryuk Signed-off-by: Ingo Molnar Reviewed-by: Juergen Gross Cc: Boris Ostrovsky Cc: "H. Peter Anvin" Cc: "Xin Li (Intel)" Link: https://lore.kernel.org/r/20250410193106.16353-1-jason.andryuk@amd.com --- arch/x86/xen/enlighten.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 1b7710bd0d05..53282dc7d5ac 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -103,10 +103,6 @@ noinstr void *__xen_hypercall_setfunc(void) void (*func)(void); /* - * Xen is supported only on CPUs with CPUID, so testing for - * X86_FEATURE_CPUID is a test for early_cpu_init() having been - * run. - * * Note that __xen_hypercall_setfunc() is noinstr only due to a nasty * dependency chain: it is being called via the xen_hypercall static * call when running as a PVH or HVM guest. Hypercalls need to be @@ -118,8 +114,7 @@ noinstr void *__xen_hypercall_setfunc(void) */ instrumentation_begin(); - if (!boot_cpu_has(X86_FEATURE_CPUID)) - xen_get_vendor(); + xen_get_vendor(); if ((boot_cpu_data.x86_vendor == X86_VENDOR_AMD || boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)) From 805b743fc163f1abef7ce1bea8eca8dfab5b685b Mon Sep 17 00:00:00 2001 From: "Borislav Petkov (AMD)" Date: Thu, 10 Apr 2025 13:42:22 +0200 Subject: [PATCH 2/5] x86/microcode/AMD: Extend the SHA check to Zen5, block loading of any unreleased standalone Zen5 microcode patches All Zen5 machines out there should get BIOS updates which update to the correct microcode patches addressing the microcode signature issue. However, silly people carve out random microcode blobs from BIOS packages and think are doing other people a service this way... Block loading of any unreleased standalone Zen5 microcode patches. Signed-off-by: Borislav Petkov (AMD) Signed-off-by: Ingo Molnar Cc: Cc: Andrew Cooper Cc: Boris Ostrovsky Cc: Linus Torvalds Cc: Maciej S. Szmigiero Cc: Nikolay Borisov Cc: Tom Lendacky Link: https://lore.kernel.org/r/20250410114222.32523-1-bp@kernel.org --- arch/x86/kernel/cpu/microcode/amd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/microcode/amd.c b/arch/x86/kernel/cpu/microcode/amd.c index b61028cf5c8a..4a10d35e70aa 100644 --- a/arch/x86/kernel/cpu/microcode/amd.c +++ b/arch/x86/kernel/cpu/microcode/amd.c @@ -199,6 +199,12 @@ static bool need_sha_check(u32 cur_rev) case 0xa70c0: return cur_rev <= 0xa70C009; break; case 0xaa001: return cur_rev <= 0xaa00116; break; case 0xaa002: return cur_rev <= 0xaa00218; break; + case 0xb0021: return cur_rev <= 0xb002146; break; + case 0xb1010: return cur_rev <= 0xb101046; break; + case 0xb2040: return cur_rev <= 0xb204031; break; + case 0xb4040: return cur_rev <= 0xb404031; break; + case 0xb6000: return cur_rev <= 0xb600031; break; + case 0xb7000: return cur_rev <= 0xb700031; break; default: break; } @@ -214,8 +220,7 @@ static bool verify_sha256_digest(u32 patch_id, u32 cur_rev, const u8 *data, unsi struct sha256_state s; int i; - if (x86_family(bsp_cpuid_1_eax) < 0x17 || - x86_family(bsp_cpuid_1_eax) > 0x19) + if (x86_family(bsp_cpuid_1_eax) < 0x17) return true; if (!need_sha_check(cur_rev)) From d466304c4322ad391797437cd84cca7ce1660de0 Mon Sep 17 00:00:00 2001 From: Pi Xiange Date: Mon, 14 Apr 2025 11:28:39 +0800 Subject: [PATCH 3/5] x86/cpu: Add CPU model number for Bartlett Lake CPUs with Raptor Cove cores Bartlett Lake has a P-core only product with Raptor Cove. [ mingo: Switch around the define as pointed out by Christian Ludloff: Ratpr Cove is the core, Bartlett Lake is the product. Signed-off-by: Pi Xiange Signed-off-by: Ingo Molnar Cc: Christian Ludloff Cc: Peter Zijlstra Cc: Tony Luck Cc: Andrew Cooper Cc: "H. Peter Anvin" Cc: John Ogness Cc: "Ahmed S. Darwish" Cc: x86-cpuid@lists.linux.dev Link: https://lore.kernel.org/r/20250414032839.5368-1-xiange.pi@intel.com --- arch/x86/include/asm/intel-family.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/include/asm/intel-family.h b/arch/x86/include/asm/intel-family.h index 3a97a7eefb51..be10c188614f 100644 --- a/arch/x86/include/asm/intel-family.h +++ b/arch/x86/include/asm/intel-family.h @@ -126,6 +126,8 @@ #define INTEL_GRANITERAPIDS_X IFM(6, 0xAD) /* Redwood Cove */ #define INTEL_GRANITERAPIDS_D IFM(6, 0xAE) +#define INTEL_BARTLETTLAKE IFM(6, 0xD7) /* Raptor Cove */ + /* "Hybrid" Processors (P-Core/E-Core) */ #define INTEL_LAKEFIELD IFM(6, 0x8A) /* Sunny Cove / Tremont */ From 263e55949d8902a6a09bdb92a1ab6a3f67231abe Mon Sep 17 00:00:00 2001 From: Sandipan Das Date: Fri, 18 Apr 2025 11:49:40 +0530 Subject: [PATCH 4/5] x86/cpu/amd: Fix workaround for erratum 1054 Erratum 1054 affects AMD Zen processors that are a part of Family 17h Models 00-2Fh and the workaround is to not set HWCR[IRPerfEn]. However, when X86_FEATURE_ZEN1 was introduced, the condition to detect unaffected processors was incorrectly changed in a way that the IRPerfEn bit gets set only for unaffected Zen 1 processors. Ensure that HWCR[IRPerfEn] is set for all unaffected processors. This includes a subset of Zen 1 (Family 17h Models 30h and above) and all later processors. Also clear X86_FEATURE_IRPERF on affected processors so that the IRPerfCount register is not used by other entities like the MSR PMU driver. Fixes: 232afb557835 ("x86/CPU/AMD: Add X86_FEATURE_ZEN1") Signed-off-by: Sandipan Das Signed-off-by: Ingo Molnar Acked-by: Borislav Petkov Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/caa057a9d6f8ad579e2f1abaa71efbd5bd4eaf6d.1744956467.git.sandipan.das@amd.com --- arch/x86/kernel/cpu/amd.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index a839ff506f45..2b36379ff675 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -869,6 +869,16 @@ static void init_amd_zen1(struct cpuinfo_x86 *c) pr_notice_once("AMD Zen1 DIV0 bug detected. Disable SMT for full protection.\n"); setup_force_cpu_bug(X86_BUG_DIV0); + + /* + * Turn off the Instructions Retired free counter on machines that are + * susceptible to erratum #1054 "Instructions Retired Performance + * Counter May Be Inaccurate". + */ + if (c->x86_model < 0x30) { + msr_clear_bit(MSR_K7_HWCR, MSR_K7_HWCR_IRPERF_EN_BIT); + clear_cpu_cap(c, X86_FEATURE_IRPERF); + } } static bool cpu_has_zenbleed_microcode(void) @@ -1052,13 +1062,8 @@ static void init_amd(struct cpuinfo_x86 *c) if (!cpu_feature_enabled(X86_FEATURE_XENPV)) set_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); - /* - * Turn on the Instructions Retired free counter on machines not - * susceptible to erratum #1054 "Instructions Retired Performance - * Counter May Be Inaccurate". - */ - if (cpu_has(c, X86_FEATURE_IRPERF) && - (boot_cpu_has(X86_FEATURE_ZEN1) && c->x86_model > 0x2f)) + /* Enable the Instructions Retired free counter */ + if (cpu_has(c, X86_FEATURE_IRPERF)) msr_set_bit(MSR_K7_HWCR, MSR_K7_HWCR_IRPERF_EN_BIT); check_null_seg_clears_base(c); From d54d610243a4508183978871e5faff5502786cd4 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Thu, 17 Apr 2025 22:21:21 +0200 Subject: [PATCH 5/5] x86/boot/sev: Avoid shared GHCB page for early memory acceptance Communicating with the hypervisor using the shared GHCB page requires clearing the C bit in the mapping of that page. When executing in the context of the EFI boot services, the page tables are owned by the firmware, and this manipulation is not possible. So switch to a different API for accepting memory in SEV-SNP guests, one which is actually supported at the point during boot where the EFI stub may need to accept memory, but the SEV-SNP init code has not executed yet. For simplicity, also switch the memory acceptance carried out by the decompressor when not booting via EFI - this only involves the allocation for the decompressed kernel, and is generally only called after kexec, as normal boot will jump straight into the kernel from the EFI stub. Fixes: 6c3211796326 ("x86/sev: Add SNP-specific unaccepted memory support") Tested-by: Tom Lendacky Co-developed-by: Tom Lendacky Signed-off-by: Tom Lendacky Signed-off-by: Ard Biesheuvel Signed-off-by: Ingo Molnar Cc: Cc: Dionna Amalie Glaze Cc: Kevin Loughlin Cc: Kirill A. Shutemov Cc: Linus Torvalds Cc: linux-efi@vger.kernel.org Link: https://lore.kernel.org/r/20250404082921.2767593-8-ardb+git@google.com # discussion thread #1 Link: https://lore.kernel.org/r/20250410132850.3708703-2-ardb+git@google.com # discussion thread #2 Link: https://lore.kernel.org/r/20250417202120.1002102-2-ardb+git@google.com # final submission --- arch/x86/boot/compressed/mem.c | 5 ++- arch/x86/boot/compressed/sev.c | 67 ++++++++-------------------------- arch/x86/boot/compressed/sev.h | 2 + 3 files changed, 21 insertions(+), 53 deletions(-) diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c index dbba332e4a12..f676156d9f3d 100644 --- a/arch/x86/boot/compressed/mem.c +++ b/arch/x86/boot/compressed/mem.c @@ -34,11 +34,14 @@ static bool early_is_tdx_guest(void) void arch_accept_memory(phys_addr_t start, phys_addr_t end) { + static bool sevsnp; + /* Platform-specific memory-acceptance call goes here */ if (early_is_tdx_guest()) { if (!tdx_accept_memory(start, end)) panic("TDX: Failed to accept memory\n"); - } else if (sev_snp_enabled()) { + } else if (sevsnp || (sev_get_status() & MSR_AMD64_SEV_SNP_ENABLED)) { + sevsnp = true; snp_accept_memory(start, end); } else { error("Cannot accept memory: unknown platform\n"); diff --git a/arch/x86/boot/compressed/sev.c b/arch/x86/boot/compressed/sev.c index bb55934c1cee..89ba168f4f0f 100644 --- a/arch/x86/boot/compressed/sev.c +++ b/arch/x86/boot/compressed/sev.c @@ -164,10 +164,7 @@ bool sev_snp_enabled(void) static void __page_state_change(unsigned long paddr, enum psc_op op) { - u64 val; - - if (!sev_snp_enabled()) - return; + u64 val, msr; /* * If private -> shared then invalidate the page before requesting the @@ -176,6 +173,9 @@ static void __page_state_change(unsigned long paddr, enum psc_op op) if (op == SNP_PAGE_STATE_SHARED) pvalidate_4k_page(paddr, paddr, false); + /* Save the current GHCB MSR value */ + msr = sev_es_rd_ghcb_msr(); + /* Issue VMGEXIT to change the page state in RMP table. */ sev_es_wr_ghcb_msr(GHCB_MSR_PSC_REQ_GFN(paddr >> PAGE_SHIFT, op)); VMGEXIT(); @@ -185,6 +185,9 @@ static void __page_state_change(unsigned long paddr, enum psc_op op) if ((GHCB_RESP_CODE(val) != GHCB_MSR_PSC_RESP) || GHCB_MSR_PSC_RESP_VAL(val)) sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC); + /* Restore the GHCB MSR value */ + sev_es_wr_ghcb_msr(msr); + /* * Now that page state is changed in the RMP table, validate it so that it is * consistent with the RMP entry. @@ -195,11 +198,17 @@ static void __page_state_change(unsigned long paddr, enum psc_op op) void snp_set_page_private(unsigned long paddr) { + if (!sev_snp_enabled()) + return; + __page_state_change(paddr, SNP_PAGE_STATE_PRIVATE); } void snp_set_page_shared(unsigned long paddr) { + if (!sev_snp_enabled()) + return; + __page_state_change(paddr, SNP_PAGE_STATE_SHARED); } @@ -223,56 +232,10 @@ static bool early_setup_ghcb(void) return true; } -static phys_addr_t __snp_accept_memory(struct snp_psc_desc *desc, - phys_addr_t pa, phys_addr_t pa_end) -{ - struct psc_hdr *hdr; - struct psc_entry *e; - unsigned int i; - - hdr = &desc->hdr; - memset(hdr, 0, sizeof(*hdr)); - - e = desc->entries; - - i = 0; - while (pa < pa_end && i < VMGEXIT_PSC_MAX_ENTRY) { - hdr->end_entry = i; - - e->gfn = pa >> PAGE_SHIFT; - e->operation = SNP_PAGE_STATE_PRIVATE; - if (IS_ALIGNED(pa, PMD_SIZE) && (pa_end - pa) >= PMD_SIZE) { - e->pagesize = RMP_PG_SIZE_2M; - pa += PMD_SIZE; - } else { - e->pagesize = RMP_PG_SIZE_4K; - pa += PAGE_SIZE; - } - - e++; - i++; - } - - if (vmgexit_psc(boot_ghcb, desc)) - sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC); - - pvalidate_pages(desc); - - return pa; -} - void snp_accept_memory(phys_addr_t start, phys_addr_t end) { - struct snp_psc_desc desc = {}; - unsigned int i; - phys_addr_t pa; - - if (!boot_ghcb && !early_setup_ghcb()) - sev_es_terminate(SEV_TERM_SET_LINUX, GHCB_TERM_PSC); - - pa = start; - while (pa < end) - pa = __snp_accept_memory(&desc, pa, end); + for (phys_addr_t pa = start; pa < end; pa += PAGE_SIZE) + __page_state_change(pa, SNP_PAGE_STATE_PRIVATE); } void sev_es_shutdown_ghcb(void) diff --git a/arch/x86/boot/compressed/sev.h b/arch/x86/boot/compressed/sev.h index fc725a981b09..4e463f33186d 100644 --- a/arch/x86/boot/compressed/sev.h +++ b/arch/x86/boot/compressed/sev.h @@ -12,11 +12,13 @@ bool sev_snp_enabled(void); void snp_accept_memory(phys_addr_t start, phys_addr_t end); +u64 sev_get_status(void); #else static inline bool sev_snp_enabled(void) { return false; } static inline void snp_accept_memory(phys_addr_t start, phys_addr_t end) { } +static inline u64 sev_get_status(void) { return 0; } #endif