Commit 2b7e2530 authored by Xin Li (Intel)'s avatar Xin Li (Intel) Committed by Ingo Molnar
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x86/xen/msr: Remove the error pointer argument from set_seg() 



set_seg() is used to write the following MSRs on Xen:

    MSR_FS_BASE
    MSR_KERNEL_GS_BASE
    MSR_GS_BASE

But none of these MSRs are written using any MSR write safe API.
Therefore there is no need to pass an error pointer argument to
set_seg() for returning an error code to be used in MSR safe APIs.

Remove the error pointer argument.

Signed-off-by: default avatarXin Li (Intel) <xin@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Acked-by: default avatarPeter 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/20250427092027.1598740-13-xin@zytor.com
parent f7998621

arch/x86/xen/enlighten_pv.c

+5 −11
Original line number Diff line number Diff line
@@ -1111,17 +1111,11 @@ static u64 xen_do_read_msr(unsigned int msr, int *err) 
	return val;

}



static void set_seg(unsigned int which, unsigned int low, unsigned int high,

		    int *err)

static void set_seg(u32 which, u32 low, u32 high)

{

	u64 base = ((u64)high << 32) | low;



	if (HYPERVISOR_set_segment_base(which, base) == 0)

		return;



	if (err)

		*err = -EIO;

	else

	if (HYPERVISOR_set_segment_base(which, base))

		WARN(1, "Xen set_segment_base(%u, %llx) failed\n", which, base);

}
@@ -1137,15 +1131,15 @@ static void xen_do_write_msr(unsigned int msr, unsigned int low, 


	switch (msr) {

	case MSR_FS_BASE:

		set_seg(SEGBASE_FS, low, high, err);

		set_seg(SEGBASE_FS, low, high);

		break;



	case MSR_KERNEL_GS_BASE:

		set_seg(SEGBASE_GS_USER, low, high, err);

		set_seg(SEGBASE_GS_USER, low, high);

		break;



	case MSR_GS_BASE:

		set_seg(SEGBASE_GS_KERNEL, low, high, err);

		set_seg(SEGBASE_GS_KERNEL, low, high);

		break;



	case MSR_STAR: