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KVM: arm64: Abstract set/clear of CPTR_EL2 bits behind helper

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The same traps controlled by CPTR_EL2 or CPACR_EL1 need to be
toggled in different parts of the code, but the exact bits and
their polarity differ between these two formats and the mode
(vhe/nvhe/hvhe).

To reduce the amount of duplicated code and the chance of getting
the wrong bit/polarity or missing a field, abstract the set/clear
of CPTR_EL2 bits behind a helper.

Since (h)VHE is the way of the future, use the CPACR_EL1 format,
which is a subset of the VHE CPTR_EL2, as a reference.

No functional change intended.

Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Fuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20240603122852.3923848-4-tabba@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Fuad Tabba 2024-06-03 13:28:45 +01:00 committed by Marc Zyngier
parent 45f4ea9bcf
commit 6d8fb3cbf7
4 changed files with 73 additions and 19 deletions
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6
arch/arm64/include/asm/kvm_arm.h
View File

@ -305,6 +305,12 @@
GENMASK(19, 14) | \
BIT(11))
#define CPTR_VHE_EL2_RES0 (GENMASK(63, 32) | \
GENMASK(27, 26) | \
GENMASK(23, 22) | \
GENMASK(19, 18) | \
GENMASK(15, 0))
/* Hyp Debug Configuration Register bits */
#define MDCR_EL2_E2TB_MASK (UL(0x3))
#define MDCR_EL2_E2TB_SHIFT (UL(24))

62
arch/arm64/include/asm/kvm_emulate.h
View File

@ -557,6 +557,68 @@ static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu)
vcpu_set_flag((v), e); \
} while (0)
#define __build_check_all_or_none(r, bits) \
BUILD_BUG_ON(((r) & (bits)) && ((r) & (bits)) != (bits))
#define __cpacr_to_cptr_clr(clr, set) \
({ \
u64 cptr = 0; \
\
if ((set) & CPACR_ELx_FPEN) \
cptr |= CPTR_EL2_TFP; \
if ((set) & CPACR_ELx_ZEN) \
cptr |= CPTR_EL2_TZ; \
if ((set) & CPACR_ELx_SMEN) \
cptr |= CPTR_EL2_TSM; \
if ((clr) & CPACR_ELx_TTA) \
cptr |= CPTR_EL2_TTA; \
if ((clr) & CPTR_EL2_TAM) \
cptr |= CPTR_EL2_TAM; \
if ((clr) & CPTR_EL2_TCPAC) \
cptr |= CPTR_EL2_TCPAC; \
\
cptr; \
})
#define __cpacr_to_cptr_set(clr, set) \
({ \
u64 cptr = 0; \
\
if ((clr) & CPACR_ELx_FPEN) \
cptr |= CPTR_EL2_TFP; \
if ((clr) & CPACR_ELx_ZEN) \
cptr |= CPTR_EL2_TZ; \
if ((clr) & CPACR_ELx_SMEN) \
cptr |= CPTR_EL2_TSM; \
if ((set) & CPACR_ELx_TTA) \
cptr |= CPTR_EL2_TTA; \
if ((set) & CPTR_EL2_TAM) \
cptr |= CPTR_EL2_TAM; \
if ((set) & CPTR_EL2_TCPAC) \
cptr |= CPTR_EL2_TCPAC; \
\
cptr; \
})
#define cpacr_clear_set(clr, set) \
do { \
BUILD_BUG_ON((set) & CPTR_VHE_EL2_RES0); \
BUILD_BUG_ON((clr) & CPACR_ELx_E0POE); \
__build_check_all_or_none((clr), CPACR_ELx_FPEN); \
__build_check_all_or_none((set), CPACR_ELx_FPEN); \
__build_check_all_or_none((clr), CPACR_ELx_ZEN); \
__build_check_all_or_none((set), CPACR_ELx_ZEN); \
__build_check_all_or_none((clr), CPACR_ELx_SMEN); \
__build_check_all_or_none((set), CPACR_ELx_SMEN); \
\
if (has_vhe() || has_hvhe()) \
sysreg_clear_set(cpacr_el1, clr, set); \
else \
sysreg_clear_set(cptr_el2, \
__cpacr_to_cptr_clr(clr, set), \
__cpacr_to_cptr_set(clr, set));\
} while (0)
static __always_inline void kvm_write_cptr_el2(u64 val)
{
if (has_vhe() || has_hvhe())

18
arch/arm64/kvm/hyp/include/hyp/switch.h
View File

@ -331,7 +331,6 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
{
bool sve_guest;
u8 esr_ec;
u64 reg;
if (!system_supports_fpsimd())
return false;
@ -354,19 +353,10 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
/* Valid trap. Switch the context: */
/* First disable enough traps to allow us to update the registers */
if (has_vhe() || has_hvhe()) {
reg = CPACR_EL1_FPEN_EL0EN | CPACR_EL1_FPEN_EL1EN;
if (sve_guest)
reg |= CPACR_EL1_ZEN_EL0EN | CPACR_EL1_ZEN_EL1EN;
sysreg_clear_set(cpacr_el1, 0, reg);
} else {
reg = CPTR_EL2_TFP;
if (sve_guest)
reg |= CPTR_EL2_TZ;
sysreg_clear_set(cptr_el2, reg, 0);
}
if (sve_guest)
cpacr_clear_set(0, CPACR_ELx_FPEN | CPACR_ELx_ZEN);
else
cpacr_clear_set(0, CPACR_ELx_FPEN);
isb();
/* Write out the host state if it's in the registers */

6
arch/arm64/kvm/hyp/nvhe/hyp-main.c
View File

@ -405,11 +405,7 @@ void handle_trap(struct kvm_cpu_context *host_ctxt)
handle_host_smc(host_ctxt);
break;
case ESR_ELx_EC_SVE:
if (has_hvhe())
sysreg_clear_set(cpacr_el1, 0, (CPACR_EL1_ZEN_EL1EN |
CPACR_EL1_ZEN_EL0EN));
else
sysreg_clear_set(cptr_el2, CPTR_EL2_TZ, 0);
cpacr_clear_set(0, CPACR_ELx_ZEN);
isb();
sve_cond_update_zcr_vq(ZCR_ELx_LEN_MASK, SYS_ZCR_EL2);
break;