From: Ankur Arora <ankur.a.arora@oracle.com>
To: linux-kernel@vger.kernel.org, x86@kernel.org
Cc: peterz@infradead.org, hpa@zytor.com, jpoimboe@redhat.com,
namit@vmware.com, mhiramat@kernel.org, jgross@suse.com,
bp@alien8.de, vkuznets@redhat.com, pbonzini@redhat.com,
boris.ostrovsky@oracle.com, mihai.carabas@oracle.com,
kvm@vger.kernel.org, xen-devel@lists.xenproject.org,
virtualization@lists.linux-foundation.org,
Ankur Arora <ankur.a.arora@oracle.com>
Subject: [RFC PATCH 07/26] x86/paravirt: Persist .parainstructions.runtime
Date: Tue, 7 Apr 2020 22:03:04 -0700 [thread overview]
Message-ID: <20200408050323.4237-8-ankur.a.arora@oracle.com> (raw)
In-Reply-To: <20200408050323.4237-1-ankur.a.arora@oracle.com>
Persist .parainstructions.runtime in memory. We will use it to
patch paravirt-ops at runtime.
The extra memory footprint depends on chosen config options but the
inlined queued_spin_unlock() presents an edge case:
$ objdump -h vmlinux|grep .parainstructions
Idx Name Size VMA
LMA File-off Algn
27 .parainstructions 0001013c ffffffff82895000
0000000002895000 01c95000 2**3
28 .parainstructions.runtime 0000cd2c ffffffff828a5140
00000000028a5140 01ca5140 2**3
(The added footprint is the size of the .parainstructions.runtime
section.)
$ size vmlinux
text data bss dec hex filename
13726196 12302814 14094336 40123346 2643bd2 vmlinux
Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
---
arch/x86/include/asm/alternative.h | 1 +
arch/x86/kernel/alternative.c | 16 +++++++++++++++-
arch/x86/kernel/module.c | 28 +++++++++++++++++++++++-----
3 files changed, 39 insertions(+), 6 deletions(-)
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index db91a7731d87..d19546c14ff6 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -76,6 +76,7 @@ extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
struct module;
void alternatives_module_add(struct module *mod, char *name,
+ void *para, void *para_end,
void *locks, void *locks_end,
void *text, void *text_end);
void alternatives_module_del(struct module *mod);
diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c
index 09e4ee0e09a2..8189ac21624c 100644
--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -482,6 +482,12 @@ struct alt_module {
struct module *mod;
char *name;
+#ifdef CONFIG_PARAVIRT_RUNTIME
+ /* ptrs to paravirt sites */
+ struct paravirt_patch_site *para;
+ struct paravirt_patch_site *para_end;
+#endif
+
/* ptrs to lock prefixes */
const s32 *locks;
const s32 *locks_end;
@@ -496,6 +502,7 @@ struct alt_module {
static LIST_HEAD(alt_modules);
void __init_or_module alternatives_module_add(struct module *mod, char *name,
+ void *para, void *para_end,
void *locks, void *locks_end,
void *text, void *text_end)
{
@@ -506,7 +513,7 @@ void __init_or_module alternatives_module_add(struct module *mod, char *name,
if (!noreplace_smp && (num_present_cpus() == 1 || setup_max_cpus <= 1))
uniproc_patched = true;
#endif
- if (!uniproc_patched)
+ if (!IS_ENABLED(CONFIG_PARAVIRT_RUNTIME) && !uniproc_patched)
return;
mutex_lock(&text_mutex);
@@ -516,6 +523,11 @@ void __init_or_module alternatives_module_add(struct module *mod, char *name,
alt->mod = mod;
alt->name = name;
+#ifdef CONFIG_PARAVIRT_RUNTIME
+ alt->para = para;
+ alt->para_end = para_end;
+#endif
+
if (num_possible_cpus() != 1 || uniproc_patched) {
/* Remember only if we'll need to undo it. */
alt->locks = locks;
@@ -733,6 +745,8 @@ void __init alternative_instructions(void)
apply_alternatives(__alt_instructions, __alt_instructions_end);
alternatives_module_add(NULL, "core kernel",
+ __parainstructions_runtime,
+ __parainstructions_runtime_end,
__smp_locks, __smp_locks_end,
_text, _etext);
diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c
index fc3d35198b09..7b2632184c11 100644
--- a/arch/x86/kernel/module.c
+++ b/arch/x86/kernel/module.c
@@ -248,12 +248,30 @@ int module_finalize(const Elf_Ehdr *hdr,
void *aseg = (void *)alt->sh_addr;
apply_alternatives(aseg, aseg + alt->sh_size);
}
- if (locks && text) {
- void *lseg = (void *)locks->sh_addr;
- void *tseg = (void *)text->sh_addr;
+ if (para_run || (locks && text)) {
+ void *pseg, *pseg_end;
+ void *lseg, *lseg_end;
+ void *tseg, *tseg_end;
+
+ pseg = pseg_end = NULL;
+ lseg = lseg_end = NULL;
+ tseg = tseg_end = NULL;
+ if (para_run) {
+ pseg = (void *)para_run->sh_addr;
+ pseg_end = pseg + para_run->sh_size;
+ }
+
+ if (locks && text) {
+ tseg = (void *)text->sh_addr;
+ tseg_end = tseg + text->sh_size;
+
+ lseg = (void *)locks->sh_addr;
+ lseg_end = lseg + locks->sh_size;
+ }
alternatives_module_add(me, me->name,
- lseg, lseg + locks->sh_size,
- tseg, tseg + text->sh_size);
+ pseg, pseg_end,
+ lseg, lseg_end,
+ tseg, tseg_end);
}
if (para) {
--
2.20.1
next prev parent reply other threads:[~2020-04-08 5:07 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-08 5:02 [RFC PATCH 00/26] Runtime paravirt patching Ankur Arora
2020-04-08 5:02 ` [RFC PATCH 01/26] x86/paravirt: Specify subsection in PVOP macros Ankur Arora
2020-04-08 5:02 ` [RFC PATCH 02/26] x86/paravirt: Allow paravirt patching post-init Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 03/26] x86/paravirt: PVRTOP macros for PARAVIRT_RUNTIME Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 04/26] x86/alternatives: Refactor alternatives_smp_module* Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 05/26] x86/alternatives: Rename alternatives_smp*, smp_alt_module Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 06/26] x86/alternatives: Remove stale symbols Ankur Arora
2020-04-08 5:03 ` Ankur Arora [this message]
2020-04-08 5:03 ` [RFC PATCH 08/26] x86/paravirt: Stash native pv-ops Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 09/26] x86/paravirt: Add runtime_patch() Ankur Arora
2020-04-08 11:05 ` Peter Zijlstra
2020-04-08 5:03 ` [RFC PATCH 10/26] x86/paravirt: Add primitives to stage pv-ops Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 11/26] x86/alternatives: Remove return value of text_poke*() Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 12/26] x86/alternatives: Use __get_unlocked_pte() in text_poke() Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 13/26] x86/alternatives: Split __text_poke() Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 14/26] x86/alternatives: Handle native insns in text_poke_loc*() Ankur Arora
2020-04-08 11:11 ` Peter Zijlstra
2020-04-08 11:17 ` Peter Zijlstra
2020-04-08 5:03 ` [RFC PATCH 15/26] x86/alternatives: Non-emulated text poking Ankur Arora
2020-04-08 11:13 ` Peter Zijlstra
2020-04-08 11:23 ` Peter Zijlstra
2020-04-08 5:03 ` [RFC PATCH 16/26] x86/alternatives: Add paravirt patching at runtime Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 17/26] x86/alternatives: Add patching logic in text_poke_site() Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 18/26] x86/alternatives: Handle BP in non-emulated text poking Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 19/26] x86/alternatives: NMI safe runtime patching Ankur Arora
2020-04-08 11:36 ` Peter Zijlstra
2020-04-08 5:03 ` [RFC PATCH 20/26] x86/paravirt: Enable pv-spinlocks in runtime_patch() Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 21/26] x86/alternatives: Paravirt runtime selftest Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 22/26] kvm/paravirt: Encapsulate KVM pv switching logic Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 23/26] x86/kvm: Add worker to trigger runtime patching Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 24/26] x86/kvm: Support dynamic CPUID hints Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 25/26] x86/kvm: Guest support for dynamic hints Ankur Arora
2020-04-08 5:03 ` [RFC PATCH 26/26] x86/kvm: Add hint change notifier for KVM_HINT_REALTIME Ankur Arora
2020-04-08 12:08 ` [RFC PATCH 00/26] Runtime paravirt patching Peter Zijlstra
2020-04-08 13:33 ` Jürgen Groß
2020-04-08 14:49 ` Peter Zijlstra
2020-04-10 9:18 ` Ankur Arora
2020-04-08 12:28 ` Jürgen Groß
2020-04-10 7:56 ` Ankur Arora
2020-04-10 9:32 ` Ankur Arora
2020-04-08 14:12 ` Thomas Gleixner
2020-04-10 9:55 ` Ankur Arora
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