x86/xen/msr: Remove pmu_msr_{read,write}()

As pmu_msr_{read,write}() are now wrappers of pmu_msr_chk_emulated(),
remove them and use pmu_msr_chk_emulated() directly.

As pmu_msr_chk_emulated() could easily return false in the cases where
it would set *emul to false, remove the "emul" argument and use the
return value instead.

While at it, convert the data type of MSR index to u32 in functions
called in pmu_msr_chk_emulated().

Suggested-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Suggested-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Link: https://lore.kernel.org/r/20250427092027.1598740-12-xin@zytor.com

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 530b59b0589ce86e5d7833eba3e0230ac9c04e87..719370d366226c6f6d5ce8c51f507d57cf6ca0a9 100644 (file)
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1091,7 +1091,7 @@ static u64 xen_do_read_msr(unsigned int msr, int *err)
 {
        u64 val = 0;    /* Avoid uninitialized value for safe variant. */
 
-       if (pmu_msr_read_emulated(msr, &val))
+       if (pmu_msr_chk_emulated(msr, &val, true))
                return val;
 
        if (err)
@@ -1163,12 +1163,13 @@ static void xen_do_write_msr(unsigned int msr, unsigned int low,
        default:
                val = (u64)high << 32 | low;
 
-               if (!pmu_msr_write_emulated(msr, val)) {
-                       if (err)
-                               *err = native_write_msr_safe(msr, low, high);
-                       else
-                               native_write_msr(msr, low, high);
-               }
+               if (pmu_msr_chk_emulated(msr, &val, false))
+                       return;
+
+               if (err)
+                       *err = native_write_msr_safe(msr, low, high);
+               else
+                       native_write_msr(msr, low, high);
        }
 }
 

diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c
index 0062dbbd6661232390505444a81cf8f9775de1b3..043d72b060eda02b2b15d729fff9d058280d6d19 100644 (file)
--- a/arch/x86/xen/pmu.c
+++ b/arch/x86/xen/pmu.c
@@ -129,7 +129,7 @@ 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)
@@ -195,8 +195,7 @@ 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;
@@ -258,7 +257,7 @@ 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;
@@ -299,33 +298,17 @@ 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)
 {
        int type, index = 0;
 
        if (is_amd_pmu_msr(msr))
-               *emul = xen_amd_pmu_emulate(msr, val, is_read);
-       else if (is_intel_pmu_msr(msr, &type, &index))
-               *emul = xen_intel_pmu_emulate(msr, val, type, index, is_read);
-       else
-               return false;
-
-       return true;
-}
-
-bool pmu_msr_read_emulated(u32 msr, u64 *val)
-{
-       bool emulated;
+               return xen_amd_pmu_emulate(msr, val, is_read);
 
-       return pmu_msr_chk_emulated(msr, val, true, &emulated) && emulated;
-}
+       if (is_intel_pmu_msr(msr, &type, &index))
+               return xen_intel_pmu_emulate(msr, val, type, index, is_read);
 
-bool pmu_msr_write_emulated(u32 msr, u64 val)
-{
-       bool emulated;
-
-       return pmu_msr_chk_emulated(msr, &val, false, &emulated) && emulated;
+       return false;
 }
 
 static u64 xen_amd_read_pmc(int counter)

diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 2de30618aa5e450672120c17a3c3b026b60811c6..090349baec0979ac5947d488e96a53659bcd38d1 100644 (file)
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -271,8 +271,7 @@ 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_emulated(u32 msr, u64 *val);
-bool pmu_msr_write_emulated(u32 msr, u64 val);
+bool pmu_msr_chk_emulated(u32 msr, u64 *val, bool is_read);
 int pmu_apic_update(uint32_t reg);
 u64 xen_read_pmc(int counter);