powerpc/pseries: Get entry and uaccess flush required bits from H_GET_CPU_CHARACTERISTICS

This allows the hypervisor / firmware to describe these workarounds to
the guest.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210503130243.891868-2-npiggin@gmail.com
This commit is contained in:
Nicholas Piggin 2021-05-03 23:02:40 +10:00 committed by Michael Ellerman
parent 710e682286
commit 65c7d07085
2 changed files with 8 additions and 0 deletions

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@ -400,6 +400,8 @@
#define H_CPU_BEHAV_FAVOUR_SECURITY_H (1ull << 60) // IBM bit 3
#define H_CPU_BEHAV_FLUSH_COUNT_CACHE (1ull << 58) // IBM bit 5
#define H_CPU_BEHAV_FLUSH_LINK_STACK (1ull << 57) // IBM bit 6
#define H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY (1ull << 56) // IBM bit 7
#define H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS (1ull << 55) // IBM bit 8
/* Flag values used in H_REGISTER_PROC_TBL hcall */
#define PROC_TABLE_OP_MASK 0x18

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@ -549,6 +549,12 @@ static void init_cpu_char_feature_flags(struct h_cpu_char_result *result)
if (!(result->behaviour & H_CPU_BEHAV_L1D_FLUSH_PR))
security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
if (result->behaviour & H_CPU_BEHAV_NO_L1D_FLUSH_ENTRY)
security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
if (result->behaviour & H_CPU_BEHAV_NO_L1D_FLUSH_UACCESS)
security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
if (!(result->behaviour & H_CPU_BEHAV_BNDS_CHK_SPEC_BAR))
security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
}