Xen-Devel Archive on lore.kernel.org
 help / color / Atom feed
From: Roger Pau Monne <roger.pau@citrix.com>
To: <xen-devel@lists.xenproject.org>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>,
	Ian Jackson <ian.jackson@eu.citrix.com>, Wei Liu <wl@xen.org>,
	Jan Beulich <jbeulich@suse.com>,
	Roger Pau Monne <roger.pau@citrix.com>
Subject: [Xen-devel] [PATCH] x86/hvmloader: align BAR position to 4K
Date: Tue, 14 Jan 2020 19:13:45 +0100
Message-ID: <20200114181345.27565-1-roger.pau@citrix.com> (raw)

When placing BARs with sizes smaller than 4K multiple BARs can end
up mapped to the same guest physical address, and thus won't work
correctly.

Align all BARs placement to 4K in hvmloader to prevent such
overlapping.

Note that the guest can still move the BARs around and create this
collisions, and that BARs not filling up a physical page might leak
access to other MMIO regions placed in the same host physical page.

This is however no worse than what's currently done, and hence should
be considered an improvement over the current state.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
---
 tools/firmware/hvmloader/pci.c  | 4 ++++
 tools/firmware/hvmloader/util.h | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
index 0b708bf578..c433b34cd6 100644
--- a/tools/firmware/hvmloader/pci.c
+++ b/tools/firmware/hvmloader/pci.c
@@ -489,6 +489,10 @@ void pci_setup(void)
 
         resource->base = base;
 
+        if ( (bar_data & PCI_BASE_ADDRESS_SPACE) ==
+             PCI_BASE_ADDRESS_SPACE_MEMORY )
+            resource->base = ROUNDUP(resource->base, PAGE_SIZE);
+
         pci_writel(devfn, bar_reg, bar_data);
         if (using_64bar)
             pci_writel(devfn, bar_reg + 4, bar_data_upper);
diff --git a/tools/firmware/hvmloader/util.h b/tools/firmware/hvmloader/util.h
index 7bca6418d2..b5554b5844 100644
--- a/tools/firmware/hvmloader/util.h
+++ b/tools/firmware/hvmloader/util.h
@@ -51,6 +51,8 @@ void __bug(char *file, int line) __attribute__((noreturn));
 #define MB(mb) (mb##ULL << 20)
 #define GB(gb) (gb##ULL << 30)
 
+#define ROUNDUP(x, a) (((x) + (a) - 1) & ~((a) - 1))
+
 static inline int test_bit(unsigned int b, const void *p)
 {
     return !!(((const uint8_t *)p)[b>>3] & (1u<<(b&7)));
-- 
2.24.1


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

             reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-14 18:13 Roger Pau Monne [this message]
2020-01-16 10:56 ` Jan Beulich
2020-01-16 19:57 ` Jason Andryuk

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200114181345.27565-1-roger.pau@citrix.com \
    --to=roger.pau@citrix.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=ian.jackson@eu.citrix.com \
    --cc=jbeulich@suse.com \
    --cc=wl@xen.org \
    --cc=xen-devel@lists.xenproject.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Xen-Devel Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/xen-devel/0 xen-devel/git/0.git
	git clone --mirror https://lore.kernel.org/xen-devel/1 xen-devel/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 xen-devel xen-devel/ https://lore.kernel.org/xen-devel \
		xen-devel@lists.xenproject.org xen-devel@lists.xen.org
	public-inbox-index xen-devel

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.xenproject.lists.xen-devel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git