Commit af94aad4 authored by Kristina Martsenko's avatar Kristina Martsenko Committed by Catalin Marinas
Browse files

KVM: arm64: initialize HCRX_EL2 



ARMv8.7/9.2 adds a new hypervisor configuration register HCRX_EL2.
Initialize the register to a safe value (all fields 0), to be robust
against firmware that has not initialized it. This is also needed to
ensure that the register is reinitialized after a kexec by a future
kernel.

In addition, move SMPME setup over to the new flags, as it would
otherwise get overridden. It is safe to set the bit even if SME is not
(uniformly) supported, as it will write to a RES0 bit (having no
effect), and SME will be disabled by the cpufeature framework.
(Similar to how e.g. the API bit is handled in HCR_HOST_NVHE_FLAGS.)

Signed-off-by: default avatarKristina Martsenko <kristina.martsenko@arm.com>
Acked-by: default avatarMarc Zyngier <maz@kernel.org>
Acked-by: default avatarOliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20230509142235.3284028-2-kristina.martsenko@arm.com


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 44c026a7

arch/arm64/include/asm/el2_setup.h

+10 −8
Original line number Diff line number Diff line
@@ -22,6 +22,15 @@ 
	isb

.endm



.macro __init_el2_hcrx

	mrs	x0, id_aa64mmfr1_el1

	ubfx	x0, x0, #ID_AA64MMFR1_EL1_HCX_SHIFT, #4

	cbz	x0, .Lskip_hcrx_\@

	mov_q	x0, HCRX_HOST_FLAGS

	msr_s	SYS_HCRX_EL2, x0

.Lskip_hcrx_\@:

.endm



/*

 * Allow Non-secure EL1 and EL0 to access physical timer and counter.

 * This is not necessary for VHE, since the host kernel runs in EL2,
@@ -184,6 +193,7 @@ 
 */

.macro init_el2_state

	__init_el2_sctlr

	__init_el2_hcrx

	__init_el2_timers

	__init_el2_debug

	__init_el2_lor
@@ -284,14 +294,6 @@ 
	cbz     x1, .Lskip_sme_\@



	msr_s	SYS_SMPRIMAP_EL2, xzr		// Make all priorities equal



	mrs	x1, id_aa64mmfr1_el1		// HCRX_EL2 present?

	ubfx	x1, x1, #ID_AA64MMFR1_EL1_HCX_SHIFT, #4

	cbz	x1, .Lskip_sme_\@



	mrs_s	x1, SYS_HCRX_EL2

	orr	x1, x1, #HCRX_EL2_SMPME_MASK	// Enable priority mapping

	msr_s	SYS_HCRX_EL2, x1

.Lskip_sme_\@:

.endm

arch/arm64/include/asm/kvm_arm.h

+3 −0
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 


#include <asm/esr.h>

#include <asm/memory.h>

#include <asm/sysreg.h>

#include <asm/types.h>



/* Hyp Configuration Register (HCR) bits */
@@ -92,6 +93,8 @@ 
#define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC)

#define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H)



#define HCRX_HOST_FLAGS (HCRX_EL2_SMPME)



/* TCR_EL2 Registers bits */

#define TCR_EL2_RES1		((1U << 31) | (1 << 23))

#define TCR_EL2_TBI		(1 << 20)