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Commit 6befd3a7 authored by Borislav Petkov's avatar Borislav Petkov Committed by Greg Kroah-Hartman
Browse files

x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host} 



commit cc69b34989210f067b2c51d5539b5f96ebcc3a01 upstream

Function bodies are very similar and are going to grow more almost
identical code. Add a bool arg to determine whether SPEC_CTRL is being set
for the guest or restored to the host.

No functional changes.

Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 3e6ab4ca

arch/x86/include/asm/spec-ctrl.h

+29 −4
Original line number Diff line number Diff line
@@ -13,10 +13,35 @@ 
 * Takes the guest view of SPEC_CTRL MSR as a parameter and also

 * the guest's version of VIRT_SPEC_CTRL, if emulated.

 */

extern void x86_spec_ctrl_set_guest(u64 guest_spec_ctrl,

				    u64 guest_virt_spec_ctrl);

extern void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl,

				       u64 guest_virt_spec_ctrl);

extern void x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool guest);



/**

 * x86_spec_ctrl_set_guest - Set speculation control registers for the guest

 * @guest_spec_ctrl:		The guest content of MSR_SPEC_CTRL

 * @guest_virt_spec_ctrl:	The guest controlled bits of MSR_VIRT_SPEC_CTRL

 *				(may get translated to MSR_AMD64_LS_CFG bits)

 *

 * Avoids writing to the MSR if the content/bits are the same

 */

static inline

void x86_spec_ctrl_set_guest(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl)

{

	x86_virt_spec_ctrl(guest_spec_ctrl, guest_virt_spec_ctrl, true);

}



/**

 * x86_spec_ctrl_restore_host - Restore host speculation control registers

 * @guest_spec_ctrl:		The guest content of MSR_SPEC_CTRL

 * @guest_virt_spec_ctrl:	The guest controlled bits of MSR_VIRT_SPEC_CTRL

 *				(may get translated to MSR_AMD64_LS_CFG bits)

 *

 * Avoids writing to the MSR if the content/bits are the same

 */

static inline

void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl)

{

	x86_virt_spec_ctrl(guest_spec_ctrl, guest_virt_spec_ctrl, false);

}



/* AMD specific Speculative Store Bypass MSR data */

extern u64 x86_amd_ls_cfg_base;

arch/x86/kernel/cpu/bugs.c

+15 −45
Original line number Diff line number Diff line
@@ -151,55 +151,25 @@ u64 x86_spec_ctrl_get_default(void) 
}

EXPORT_SYMBOL_GPL(x86_spec_ctrl_get_default);



/**

 * x86_spec_ctrl_set_guest - Set speculation control registers for the guest

 * @guest_spec_ctrl:		The guest content of MSR_SPEC_CTRL

 * @guest_virt_spec_ctrl:	The guest controlled bits of MSR_VIRT_SPEC_CTRL

 *				(may get translated to MSR_AMD64_LS_CFG bits)

 *

 * Avoids writing to the MSR if the content/bits are the same

 */

void x86_spec_ctrl_set_guest(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl)

void

x86_virt_spec_ctrl(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl, bool setguest)

{

	u64 host = x86_spec_ctrl_base;

	struct thread_info *ti = current_thread_info();

	u64 msr, host = x86_spec_ctrl_base;



	/* Is MSR_SPEC_CTRL implemented ? */

	if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))

		return;



	if (static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL)) {

		/* SSBD controlled in MSR_SPEC_CTRL */

		if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD))

		host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);

			host |= ssbd_tif_to_spec_ctrl(ti->flags);



	if (host != guest_spec_ctrl)

		wrmsrl(MSR_IA32_SPEC_CTRL, guest_spec_ctrl);

		if (host != guest_spec_ctrl) {

			msr = setguest ? guest_spec_ctrl : host;

			wrmsrl(MSR_IA32_SPEC_CTRL, msr);

		}

	}

EXPORT_SYMBOL_GPL(x86_spec_ctrl_set_guest);



/**

 * x86_spec_ctrl_restore_host - Restore host speculation control registers

 * @guest_spec_ctrl:		The guest content of MSR_SPEC_CTRL

 * @guest_virt_spec_ctrl:	The guest controlled bits of MSR_VIRT_SPEC_CTRL

 *				(may get translated to MSR_AMD64_LS_CFG bits)

 *

 * Avoids writing to the MSR if the content/bits are the same

 */

void x86_spec_ctrl_restore_host(u64 guest_spec_ctrl, u64 guest_virt_spec_ctrl)

{

	u64 host = x86_spec_ctrl_base;



	/* Is MSR_SPEC_CTRL implemented ? */

	if (!static_cpu_has(X86_FEATURE_MSR_SPEC_CTRL))

		return;



	/* SSBD controlled in MSR_SPEC_CTRL */

	if (static_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD))

		host |= ssbd_tif_to_spec_ctrl(current_thread_info()->flags);



	if (host != guest_spec_ctrl)

		wrmsrl(MSR_IA32_SPEC_CTRL, host);

}

EXPORT_SYMBOL_GPL(x86_spec_ctrl_restore_host);

EXPORT_SYMBOL_GPL(x86_virt_spec_ctrl);



static void x86_amd_ssb_disable(void)

{