Date: Sun, 30 Jul 2023 15:47:17 GMT From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 5ad29bc8d4d4 - main - amd64: Fix TLB invalidation routines in !SMP kernels Message-ID: <202307301547.36UFlHLk089123@gitrepo.freebsd.org>
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The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=5ad29bc8d4d436660954f6db507909965369fc32 commit 5ad29bc8d4d436660954f6db507909965369fc32 Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2023-07-30 15:12:35 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2023-07-30 15:12:35 +0000 amd64: Fix TLB invalidation routines in !SMP kernels amd64 is special in that its implementation of zpcpu_offset_cpu() is not the identity transformation, even in !SMP kernels. Because the pm_pcidp array of amd64's struct pmap is allocated from a pcpu UMA zone, this means that accessing pm_pcidp directly, as is done in !SMP implementations of pmap_invalidate_*, does not work. Specifically, I see occasional unexplicable crashes in userspace when PCIDs are enabled. Apply a minimal patch to fix the problem. While it would also make sense to provide separate implementations of zpcpu_* for !SMP kernels, fixing it this way makes the SMP and !SMP implementations of pmap_invalidate_* more similar. Reviewed by: alc, kib MFC after: 1 week Sponsored by: Klara, Inc. Sponsored by: Juniper Networks, Inc. Differential Revision: https://reviews.freebsd.org/D41230 --- sys/amd64/amd64/pmap.c | 46 +++++++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 17 deletions(-) diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c index c1968fc11844..5bc40bd00a32 100644 --- a/sys/amd64/amd64/pmap.c +++ b/sys/amd64/amd64/pmap.c @@ -3489,6 +3489,7 @@ void pmap_invalidate_page(pmap_t pmap, vm_offset_t va) { struct invpcid_descr d; + struct pmap_pcid *pcidp; uint64_t kcr3, ucr3; uint32_t pcid; @@ -3504,7 +3505,7 @@ pmap_invalidate_page(pmap_t pmap, vm_offset_t va) if (pmap == PCPU_GET(curpmap) && pmap_pcid_enabled && pmap->pm_ucr3 != PMAP_NO_CR3) { critical_enter(); - pcid = pmap->pm_pcidp->pm_pcid; + pcid = pmap_get_pcid(pmap); if (invpcid_works) { d.pcid = pcid | PMAP_PCID_USER_PT; d.pad = 0; @@ -3518,16 +3519,20 @@ pmap_invalidate_page(pmap_t pmap, vm_offset_t va) } critical_exit(); } - } else if (pmap_pcid_enabled) - pmap->pm_pcidp->pm_gen = 0; + } else if (pmap_pcid_enabled) { + pcidp = zpcpu_get(pmap->pm_pcidp); + pcidp->pm_gen = 0; + } } void pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) { struct invpcid_descr d; + struct pmap_pcid *pcidp; vm_offset_t addr; uint64_t kcr3, ucr3; + uint32_t pcid; if (pmap->pm_type == PT_RVI || pmap->pm_type == PT_EPT) { pmap->pm_eptgen++; @@ -3542,24 +3547,24 @@ pmap_invalidate_range(pmap_t pmap, vm_offset_t sva, vm_offset_t eva) if (pmap == PCPU_GET(curpmap) && pmap_pcid_enabled && pmap->pm_ucr3 != PMAP_NO_CR3) { critical_enter(); + pcid = pmap_get_pcid(pmap); if (invpcid_works) { - d.pcid = pmap->pm_pcidp->pm_pcid | - PMAP_PCID_USER_PT; + d.pcid = pcid | PMAP_PCID_USER_PT; d.pad = 0; d.addr = sva; for (; d.addr < eva; d.addr += PAGE_SIZE) invpcid(&d, INVPCID_ADDR); } else { - kcr3 = pmap->pm_cr3 | pmap->pm_pcidp-> - pm_pcid | CR3_PCID_SAVE; - ucr3 = pmap->pm_ucr3 | pmap->pm_pcidp-> - pm_pcid | PMAP_PCID_USER_PT | CR3_PCID_SAVE; + kcr3 = pmap->pm_cr3 | pcid | CR3_PCID_SAVE; + ucr3 = pmap->pm_ucr3 | pcid | + PMAP_PCID_USER_PT | CR3_PCID_SAVE; pmap_pti_pcid_invlrng(ucr3, kcr3, sva, eva); } critical_exit(); } } else if (pmap_pcid_enabled) { - pmap->pm_pcidp->pm_gen = 0; + pcidp = zpcpu_get(pmap->pm_pcidp); + pcidp->pm_gen = 0; } } @@ -3567,7 +3572,9 @@ void pmap_invalidate_all(pmap_t pmap) { struct invpcid_descr d; + struct pmap_pcid *pcidp; uint64_t kcr3, ucr3; + uint32_t pcid; if (pmap->pm_type == PT_RVI || pmap->pm_type == PT_EPT) { pmap->pm_eptgen++; @@ -3586,8 +3593,9 @@ pmap_invalidate_all(pmap_t pmap) } else if (pmap == PCPU_GET(curpmap)) { if (pmap_pcid_enabled) { critical_enter(); + pcid = pmap_get_pcid(pmap); if (invpcid_works) { - d.pcid = pmap->pm_pcidp->pm_pcid; + d.pcid = pcid; d.pad = 0; d.addr = 0; invpcid(&d, INVPCID_CTX); @@ -3596,10 +3604,10 @@ pmap_invalidate_all(pmap_t pmap) invpcid(&d, INVPCID_CTX); } } else { - kcr3 = pmap->pm_cr3 | pmap->pm_pcidp->pm_pcid; + kcr3 = pmap->pm_cr3 | pcid; if (pmap->pm_ucr3 != PMAP_NO_CR3) { - ucr3 = pmap->pm_ucr3 | pmap->pm_pcidp-> - pm_pcid | PMAP_PCID_USER_PT; + ucr3 = pmap->pm_ucr3 | pcid | + PMAP_PCID_USER_PT; pmap_pti_pcid_invalidate(ucr3, kcr3); } else load_cr3(kcr3); @@ -3609,7 +3617,8 @@ pmap_invalidate_all(pmap_t pmap) invltlb(); } } else if (pmap_pcid_enabled) { - pmap->pm_pcidp->pm_gen = 0; + pcidp = zpcpu_get(pmap->pm_pcidp); + pcidp->pm_gen = 0; } } @@ -3623,12 +3632,15 @@ pmap_invalidate_cache(void) static void pmap_update_pde(pmap_t pmap, vm_offset_t va, pd_entry_t *pde, pd_entry_t newpde) { + struct pmap_pcid *pcidp; pmap_update_pde_store(pmap, pde, newpde); if (pmap == kernel_pmap || pmap == PCPU_GET(curpmap)) pmap_update_pde_invalidate(pmap, va, newpde); - else - pmap->pm_pcidp->pm_gen = 0; + else { + pcidp = zpcpu_get(pmap->pm_pcidp); + pcidp->pm_gen = 0; + } } #endif /* !SMP */
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