linux-kernel - [RFC PATCH v1 07/15] x86/msr: Remove pmu_msr

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20250331082251.3171276-8-xin@zytor.com>
Date: Mon, 31 Mar 2025 01:22:43 -0700
From: "Xin Li (Intel)" <xin@...or.com>
To: linux-kernel@...r.kernel.org, linux-perf-users@...r.kernel.org,
        linux-hyperv@...r.kernel.org, virtualization@...ts.linux.dev,
        linux-edac@...r.kernel.org, kvm@...r.kernel.org,
        xen-devel@...ts.xenproject.org, linux-ide@...r.kernel.org,
        linux-pm@...r.kernel.org, bpf@...r.kernel.org, llvm@...ts.linux.dev
Cc: tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
        dave.hansen@...ux.intel.com, x86@...nel.org, hpa@...or.com,
        jgross@...e.com, andrew.cooper3@...rix.com, peterz@...radead.org,
        acme@...nel.org, namhyung@...nel.org, mark.rutland@....com,
        alexander.shishkin@...ux.intel.com, jolsa@...nel.org,
        irogers@...gle.com, adrian.hunter@...el.com, kan.liang@...ux.intel.com,
        wei.liu@...nel.org, ajay.kaher@...adcom.com,
        alexey.amakhalov@...adcom.com, bcm-kernel-feedback-list@...adcom.com,
        tony.luck@...el.com, pbonzini@...hat.com, vkuznets@...hat.com,
        seanjc@...gle.com, luto@...nel.org, boris.ostrovsky@...cle.com,
        kys@...rosoft.com, haiyangz@...rosoft.com, decui@...rosoft.com
Subject: [RFC PATCH v1 07/15] x86/msr: Remove pmu_msr_{read,write}()

Now pmu_msr_{read,write}() just do pmu_msr_chk_emulated(), so remove
them and call pmu_msr_chk_emulated() directly.

Suggested-by: H. Peter Anvin (Intel) <hpa@...or.com>
Signed-off-by: Xin Li (Intel) <xin@...or.com>
---
 arch/x86/xen/enlighten_pv.c | 17 ++++++++++-------
 arch/x86/xen/pmu.c          | 24 ++++--------------------
 arch/x86/xen/xen-ops.h      |  3 +--
 3 files changed, 15 insertions(+), 29 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 7401cce19939..a047dadf4511 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1090,8 +1090,9 @@ static void xen_write_cr4(unsigned long cr4)
 static u64 xen_do_read_msr(unsigned int msr, int *err)
 {
 	u64 val = 0;	/* Avoid uninitialized value for safe variant. */
+	bool emulated;
 
-	if (pmu_msr_read(msr, &val, err))
+	if (pmu_msr_chk_emulated(msr, &val, true, &emulated) && emulated)
 		return val;
 
 	if (err)
@@ -1134,6 +1135,7 @@ static void xen_do_write_msr(unsigned int msr, unsigned int low,
 			     unsigned int high, int *err)
 {
 	u64 val;
+	bool emulated;
 
 	switch (msr) {
 	case MSR_FS_BASE:
@@ -1163,12 +1165,13 @@ static void xen_do_write_msr(unsigned int msr, unsigned int low,
 	default:
 		val = (u64)high << 32 | low;
 
-		if (!pmu_msr_write(msr, val)) {
-			if (err)
-				*err = native_write_msr_safe(msr, val);
-			else
-				native_write_msr(msr, val);
-		}
+		if (pmu_msr_chk_emulated(msr, &val, false, &emulated) && emulated)
+			return;
+
+		if (err)
+			*err = native_write_msr_safe(msr, val);
+		else
+			native_write_msr(msr, val);
 	}
 }
 
diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c
index 1364cd3fb3ef..4d20503430dd 100644
--- a/arch/x86/xen/pmu.c
+++ b/arch/x86/xen/pmu.c
@@ -128,7 +128,7 @@ static inline uint32_t get_fam15h_addr(u32 addr)
 	return addr;
 }
 
-static inline bool is_amd_pmu_msr(unsigned int msr)
+static bool is_amd_pmu_msr(u32 msr)
 {
 	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
 	    boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
@@ -194,8 +194,7 @@ static bool is_intel_pmu_msr(u32 msr_index, int *type, int *index)
 	}
 }
 
-static bool xen_intel_pmu_emulate(unsigned int msr, u64 *val, int type,
-				  int index, bool is_read)
+static bool xen_intel_pmu_emulate(u32 msr, u64 *val, int type, int index, bool is_read)
 {
 	uint64_t *reg = NULL;
 	struct xen_pmu_intel_ctxt *ctxt;
@@ -257,7 +256,7 @@ static bool xen_intel_pmu_emulate(unsigned int msr, u64 *val, int type,
 	return false;
 }
 
-static bool xen_amd_pmu_emulate(unsigned int msr, u64 *val, bool is_read)
+static bool xen_amd_pmu_emulate(u32 msr, u64 *val, bool is_read)
 {
 	uint64_t *reg = NULL;
 	int i, off = 0;
@@ -298,8 +297,7 @@ static bool xen_amd_pmu_emulate(unsigned int msr, u64 *val, bool is_read)
 	return false;
 }
 
-static bool pmu_msr_chk_emulated(unsigned int msr, uint64_t *val, bool is_read,
-				 bool *emul)
+bool pmu_msr_chk_emulated(u32 msr, u64 *val, bool is_read, bool *emul)
 {
 	int type, index = 0;
 
@@ -313,20 +311,6 @@ static bool pmu_msr_chk_emulated(unsigned int msr, uint64_t *val, bool is_read,
 	return true;
 }
 
-bool pmu_msr_read(u32 msr, u64 *val, int *err)
-{
-	bool emulated;
-
-	return pmu_msr_chk_emulated(msr, val, true, &emulated) && emulated;
-}
-
-bool pmu_msr_write(u32 msr, u64 val)
-{
-	bool emulated;
-
-	return pmu_msr_chk_emulated(msr, &val, false, &emulated) && emulated;
-}
-
 static unsigned long long xen_amd_read_pmc(int counter)
 {
 	struct xen_pmu_amd_ctxt *ctxt;
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 4a0a1d73d8b8..6545661010ce 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -274,8 +274,7 @@ void xen_pmu_finish(int cpu);
 static inline void xen_pmu_init(int cpu) {}
 static inline void xen_pmu_finish(int cpu) {}
 #endif
-bool pmu_msr_read(u32 msr, u64 *val, int *err);
-bool pmu_msr_write(u32 msr, u64 val);
+bool pmu_msr_chk_emulated(u32 msr, u64 *val, bool is_read, bool *emul);
 int pmu_apic_update(uint32_t reg);
 unsigned long long xen_read_pmc(int counter);
 
-- 
2.49.0