From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Catalin Marinas <catalin.marinas@arm.com>,
James Morse <james.morse@arm.com>
Subject: [PATCH 5.10 38/58] KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A
Date: Thu, 10 Mar 2022 15:18:58 +0100 [thread overview]
Message-ID: <20220310140813.956533242@linuxfoundation.org> (raw)
In-Reply-To: <20220310140812.869208747@linuxfoundation.org>
From: James Morse <james.morse@arm.com>
commit 5bdf3437603d4af87f9c7f424b0c8aeed2420745 upstream.
CPUs vulnerable to Spectre-BHB either need to make an SMC-CC firmware
call from the vectors, or run a sequence of branches. This gets added
to the hyp vectors. If there is no support for arch-workaround-1 in
firmware, the indirect vector will be used.
kvm_init_vector_slots() only initialises the two indirect slots if
the platform is vulnerable to Spectre-v3a. pKVM's hyp_map_vectors()
only initialises __hyp_bp_vect_base if the platform is vulnerable to
Spectre-v3a.
As there are about to more users of the indirect vectors, ensure
their entries in hyp_spectre_vector_selector[] are always initialised,
and __hyp_bp_vect_base defaults to the regular VA mapping.
The Spectre-v3a check is moved to a helper
kvm_system_needs_idmapped_vectors(), and merged with the code
that creates the hyp mappings.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/arm64/include/asm/cpucaps.h | 3 +
arch/arm64/include/asm/kvm_asm.h | 6 +++
arch/arm64/include/asm/kvm_mmu.h | 3 +
arch/arm64/include/asm/mmu.h | 6 +++
arch/arm64/kernel/proton-pack.c | 47 +++++++++++++++++++++++++++
arch/arm64/kvm/arm.c | 3 +
arch/arm64/kvm/hyp/smccc_wa.S | 66 +++++++++++++++++++++++++++++++++++++++
7 files changed, 130 insertions(+), 4 deletions(-)
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -66,7 +66,8 @@
#define ARM64_HAS_TLB_RANGE 56
#define ARM64_MTE 57
#define ARM64_WORKAROUND_1508412 58
+#define ARM64_SPECTRE_BHB 59
-#define ARM64_NCAPS 59
+#define ARM64_NCAPS 60
#endif /* __ASM_CPUCAPS_H */
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -35,6 +35,8 @@
#define KVM_VECTOR_PREAMBLE (2 * AARCH64_INSN_SIZE)
#define __SMCCC_WORKAROUND_1_SMC_SZ 36
+#define __SMCCC_WORKAROUND_3_SMC_SZ 36
+#define __SPECTRE_BHB_LOOP_SZ 44
#define KVM_HOST_SMCCC_ID(id) \
ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \
@@ -199,6 +201,10 @@ extern void __vgic_v3_init_lrs(void);
extern u32 __kvm_get_mdcr_el2(void);
extern char __smccc_workaround_1_smc[__SMCCC_WORKAROUND_1_SMC_SZ];
+extern char __smccc_workaround_3_smc[__SMCCC_WORKAROUND_3_SMC_SZ];
+extern char __spectre_bhb_loop_k8[__SPECTRE_BHB_LOOP_SZ];
+extern char __spectre_bhb_loop_k24[__SPECTRE_BHB_LOOP_SZ];
+extern char __spectre_bhb_loop_k32[__SPECTRE_BHB_LOOP_SZ];
/*
* Obtain the PC-relative address of a kernel symbol
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -237,7 +237,8 @@ static inline void *kvm_get_hyp_vector(v
void *vect = kern_hyp_va(kvm_ksym_ref(__kvm_hyp_vector));
int slot = -1;
- if (cpus_have_const_cap(ARM64_SPECTRE_V2) && data->fn) {
+ if ((cpus_have_const_cap(ARM64_SPECTRE_V2) ||
+ cpus_have_const_cap(ARM64_SPECTRE_BHB)) && data->template_start) {
vect = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs));
slot = data->hyp_vectors_slot;
}
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -67,6 +67,12 @@ typedef void (*bp_hardening_cb_t)(void);
struct bp_hardening_data {
int hyp_vectors_slot;
bp_hardening_cb_t fn;
+
+ /*
+ * template_start is only used by the BHB mitigation to identify the
+ * hyp_vectors_slot sequence.
+ */
+ const char *template_start;
};
DECLARE_PER_CPU_READ_MOSTLY(struct bp_hardening_data, bp_hardening_data);
--- a/arch/arm64/kernel/proton-pack.c
+++ b/arch/arm64/kernel/proton-pack.c
@@ -220,9 +220,9 @@ static void __copy_hyp_vect_bpi(int slot
__flush_icache_range((uintptr_t)dst, (uintptr_t)dst + SZ_2K);
}
+static DEFINE_RAW_SPINLOCK(bp_lock);
static void install_bp_hardening_cb(bp_hardening_cb_t fn)
{
- static DEFINE_RAW_SPINLOCK(bp_lock);
int cpu, slot = -1;
const char *hyp_vecs_start = __smccc_workaround_1_smc;
const char *hyp_vecs_end = __smccc_workaround_1_smc +
@@ -253,6 +253,7 @@ static void install_bp_hardening_cb(bp_h
__this_cpu_write(bp_hardening_data.hyp_vectors_slot, slot);
__this_cpu_write(bp_hardening_data.fn, fn);
+ __this_cpu_write(bp_hardening_data.template_start, hyp_vecs_start);
raw_spin_unlock(&bp_lock);
}
#else
@@ -819,3 +820,47 @@ enum mitigation_state arm64_get_spectre_
{
return spectre_bhb_state;
}
+
+static int kvm_bhb_get_vecs_size(const char *start)
+{
+ if (start == __smccc_workaround_3_smc)
+ return __SMCCC_WORKAROUND_3_SMC_SZ;
+ else if (start == __spectre_bhb_loop_k8 ||
+ start == __spectre_bhb_loop_k24 ||
+ start == __spectre_bhb_loop_k32)
+ return __SPECTRE_BHB_LOOP_SZ;
+
+ return 0;
+}
+
+void kvm_setup_bhb_slot(const char *hyp_vecs_start)
+{
+ int cpu, slot = -1, size;
+ const char *hyp_vecs_end;
+
+ if (!IS_ENABLED(CONFIG_KVM) || !is_hyp_mode_available())
+ return;
+
+ size = kvm_bhb_get_vecs_size(hyp_vecs_start);
+ if (WARN_ON_ONCE(!hyp_vecs_start || !size))
+ return;
+ hyp_vecs_end = hyp_vecs_start + size;
+
+ raw_spin_lock(&bp_lock);
+ for_each_possible_cpu(cpu) {
+ if (per_cpu(bp_hardening_data.template_start, cpu) == hyp_vecs_start) {
+ slot = per_cpu(bp_hardening_data.hyp_vectors_slot, cpu);
+ break;
+ }
+ }
+
+ if (slot == -1) {
+ slot = atomic_inc_return(&arm64_el2_vector_last_slot);
+ BUG_ON(slot >= BP_HARDEN_EL2_SLOTS);
+ __copy_hyp_vect_bpi(slot, hyp_vecs_start, hyp_vecs_end);
+ }
+
+ __this_cpu_write(bp_hardening_data.hyp_vectors_slot, slot);
+ __this_cpu_write(bp_hardening_data.template_start, hyp_vecs_start);
+ raw_spin_unlock(&bp_lock);
+}
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1337,7 +1337,8 @@ static int kvm_map_vectors(void)
* !SV2 + HEL2 -> allocate one vector slot and use exec mapping
* SV2 + HEL2 -> use hardened vectors and use exec mapping
*/
- if (cpus_have_const_cap(ARM64_SPECTRE_V2)) {
+ if (cpus_have_const_cap(ARM64_SPECTRE_V2) ||
+ cpus_have_const_cap(ARM64_SPECTRE_BHB)) {
__kvm_bp_vect_base = kvm_ksym_ref(__bp_harden_hyp_vecs);
__kvm_bp_vect_base = kern_hyp_va(__kvm_bp_vect_base);
}
--- a/arch/arm64/kvm/hyp/smccc_wa.S
+++ b/arch/arm64/kvm/hyp/smccc_wa.S
@@ -30,3 +30,69 @@ SYM_DATA_START(__smccc_workaround_1_smc)
1: .org __smccc_workaround_1_smc + __SMCCC_WORKAROUND_1_SMC_SZ
.org 1b
SYM_DATA_END(__smccc_workaround_1_smc)
+
+ .global __smccc_workaround_3_smc
+SYM_DATA_START(__smccc_workaround_3_smc)
+ esb
+ sub sp, sp, #(8 * 4)
+ stp x2, x3, [sp, #(8 * 0)]
+ stp x0, x1, [sp, #(8 * 2)]
+ mov w0, #ARM_SMCCC_ARCH_WORKAROUND_3
+ smc #0
+ ldp x2, x3, [sp, #(8 * 0)]
+ ldp x0, x1, [sp, #(8 * 2)]
+ add sp, sp, #(8 * 4)
+1: .org __smccc_workaround_3_smc + __SMCCC_WORKAROUND_3_SMC_SZ
+ .org 1b
+SYM_DATA_END(__smccc_workaround_3_smc)
+
+ .global __spectre_bhb_loop_k8
+SYM_DATA_START(__spectre_bhb_loop_k8)
+ esb
+ sub sp, sp, #(8 * 2)
+ stp x0, x1, [sp, #(8 * 0)]
+ mov x0, #8
+2: b . + 4
+ subs x0, x0, #1
+ b.ne 2b
+ dsb nsh
+ isb
+ ldp x0, x1, [sp, #(8 * 0)]
+ add sp, sp, #(8 * 2)
+1: .org __spectre_bhb_loop_k8 + __SPECTRE_BHB_LOOP_SZ
+ .org 1b
+SYM_DATA_END(__spectre_bhb_loop_k8)
+
+ .global __spectre_bhb_loop_k24
+SYM_DATA_START(__spectre_bhb_loop_k24)
+ esb
+ sub sp, sp, #(8 * 2)
+ stp x0, x1, [sp, #(8 * 0)]
+ mov x0, #8
+2: b . + 4
+ subs x0, x0, #1
+ b.ne 2b
+ dsb nsh
+ isb
+ ldp x0, x1, [sp, #(8 * 0)]
+ add sp, sp, #(8 * 2)
+1: .org __spectre_bhb_loop_k24 + __SPECTRE_BHB_LOOP_SZ
+ .org 1b
+SYM_DATA_END(__spectre_bhb_loop_k24)
+
+ .global __spectre_bhb_loop_k32
+SYM_DATA_START(__spectre_bhb_loop_k32)
+ esb
+ sub sp, sp, #(8 * 2)
+ stp x0, x1, [sp, #(8 * 0)]
+ mov x0, #8
+2: b . + 4
+ subs x0, x0, #1
+ b.ne 2b
+ dsb nsh
+ isb
+ ldp x0, x1, [sp, #(8 * 0)]
+ add sp, sp, #(8 * 2)
+1: .org __spectre_bhb_loop_k32 + __SPECTRE_BHB_LOOP_SZ
+ .org 1b
+SYM_DATA_END(__spectre_bhb_loop_k32)
next prev parent reply other threads:[~2022-03-10 14:33 UTC|newest]
Thread overview: 74+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-10 14:18 [PATCH 5.10 00/58] 5.10.105-rc2 review Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 01/58] x86,bugs: Unconditionally allow spectre_v2=retpoline,amd Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 02/58] x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 03/58] x86/speculation: Add eIBRS + Retpoline options Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 04/58] Documentation/hw-vuln: Update spectre doc Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 05/58] x86/speculation: Include unprivileged eBPF status in Spectre v2 mitigation reporting Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 06/58] x86/speculation: Use generic retpoline by default on AMD Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 07/58] x86/speculation: Update link to AMD speculation whitepaper Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 08/58] x86/speculation: Warn about Spectre v2 LFENCE mitigation Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 09/58] x86/speculation: Warn about eIBRS + LFENCE + Unprivileged eBPF + SMT Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 10/58] ARM: report Spectre v2 status through sysfs Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 11/58] ARM: early traps initialisation Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 12/58] ARM: use LOADADDR() to get load address of sections Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 13/58] ARM: Spectre-BHB workaround Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 14/58] ARM: include unprivileged BPF status in Spectre V2 reporting Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 15/58] arm64: cputype: Add CPU implementor & types for the Apple M1 cores Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 16/58] arm64: Add Neoverse-N2, Cortex-A710 CPU part definition Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 17/58] arm64: Add Cortex-X2 " Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 18/58] arm64: Add Cortex-A510 " Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 19/58] arm64: Add HWCAP for self-synchronising virtual counter Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 20/58] arm64: add ID_AA64ISAR2_EL1 sys register Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 21/58] arm64: cpufeature: add HWCAP for FEAT_AFP Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 22/58] arm64: cpufeature: add HWCAP for FEAT_RPRES Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 23/58] arm64: entry.S: Add ventry overflow sanity checks Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 24/58] arm64: spectre: Rename spectre_v4_patch_fw_mitigation_conduit Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 25/58] arm64: entry: Make the trampoline cleanup optional Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 26/58] arm64: entry: Free up another register on kptis tramp_exit path Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 27/58] arm64: entry: Move the trampoline data page before the text page Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 28/58] arm64: entry: Allow tramp_alias to access symbols after the 4K boundary Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 29/58] arm64: entry: Dont assume tramp_vectors is the start of the vectors Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 30/58] arm64: entry: Move trampoline macros out of ifdefd section Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 31/58] arm64: entry: Make the kpti trampolines kpti sequence optional Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 32/58] arm64: entry: Allow the trampoline text to occupy multiple pages Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 33/58] arm64: entry: Add non-kpti __bp_harden_el1_vectors for mitigations Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 34/58] arm64: entry: Add vectors that have the bhb mitigation sequences Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 35/58] arm64: entry: Add macro for reading symbol addresses from the trampoline Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 36/58] arm64: Add percpu vectors for EL1 Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 37/58] arm64: proton-pack: Report Spectre-BHB vulnerabilities as part of Spectre-v2 Greg Kroah-Hartman
2022-03-10 14:18 ` Greg Kroah-Hartman [this message]
2022-03-10 23:48 ` [PATCH 5.10 38/58] KVM: arm64: Allow indirect vectors to be used without SPECTRE_V3A Pavel Machek
2022-03-11 6:42 ` Greg Kroah-Hartman
2022-03-15 12:20 ` James Morse
2022-03-15 12:27 ` James Morse
2022-03-15 12:41 ` Greg Kroah-Hartman
2022-03-15 12:29 ` Greg Kroah-Hartman
2022-03-10 14:18 ` [PATCH 5.10 39/58] arm64: Mitigate spectre style branch history side channels Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 40/58] KVM: arm64: Allow SMCCC_ARCH_WORKAROUND_3 to be discovered and migrated Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 41/58] arm64: Use the clearbhb instruction in mitigations Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 42/58] arm64: proton-pack: Include unprivileged eBPF status in Spectre v2 mitigation reporting Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 43/58] ARM: fix build error when BPF_SYSCALL is disabled Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 44/58] ARM: fix co-processor register typo Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 45/58] ARM: Do not use NOCROSSREFS directive with ld.lld Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 46/58] ARM: fix build warning in proc-v7-bugs.c Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 47/58] xen/xenbus: dont let xenbus_grant_ring() remove grants in error case Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 48/58] xen/grant-table: add gnttab_try_end_foreign_access() Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 49/58] xen/blkfront: dont use gnttab_query_foreign_access() for mapped status Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 50/58] xen/netfront: " Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 51/58] xen/scsifront: " Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 52/58] xen/gntalloc: dont use gnttab_query_foreign_access() Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 53/58] xen: remove gnttab_query_foreign_access() Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 54/58] xen/9p: use alloc/free_pages_exact() Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 55/58] xen/pvcalls: " Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 56/58] xen/gnttab: fix gnttab_end_foreign_access() without page specified Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 57/58] xen/netfront: react properly to failing gnttab_end_foreign_access_ref() Greg Kroah-Hartman
2022-03-10 14:19 ` [PATCH 5.10 58/58] Revert "ACPI: PM: s2idle: Cancel wakeup before dispatching EC GPE" Greg Kroah-Hartman
2022-03-10 17:59 ` [PATCH 5.10 00/58] 5.10.105-rc2 review Pavel Machek
2022-03-10 18:48 ` Jon Hunter
2022-03-10 19:33 ` Shuah Khan
2022-03-10 22:36 ` Florian Fainelli
2022-03-11 1:04 ` Guenter Roeck
2022-03-11 6:48 ` Bagas Sanjaya
2022-03-11 10:11 ` Sudip Mukherjee
2022-03-11 11:52 ` Naresh Kamboju
2022-03-12 1:22 ` Fox Chen
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